000 FXUS62 KMHX 080805 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 405 AM EDT WED SEP 8 2010 .SYNOPSIS... HIGH PRESSURE WILL BE CENTERED OFF THE COAST TODAY. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS AFTERNOON AND CROSS THE AREA OVERNIGHT. WEAK HIGH PRESSURE WILL BUILD TO THE NORTHWEST THURSDAY AND FRIDAY THEN CROSS THE AREA ON SATURDAY BEFORE MOVING OFFSHORE. A COLD FRONT WILL APPROACH FROM THE NORTHWEST SATURDAY NIGHT AND MOVE THROUGH THE AREA LATE SUNDAY. HIGH PRESSURE RETURNS TO THE AREA EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... A MORE ZONAL FLOW WILL ESTABLISH OVER THE AREA TODAY AS A SHEARING SHORT WAVE IN THE WESTERLIES OVR THE NORTHERN MID ATLC REGION SUPRESSES THE STRONG UPPER RIDGE OVER THE SE STATES. A WARM AND SOMEWHAT BREEZY DAY WILL RESULT WITH HIGHS REACHING INTO THE LOWER 90S INLAND. MAY REACH INTO THE UPPER 80S/NEAR 90 FOR THE NORTHERN OUTER BANKS BUT WIND OFF THE COOLER SOUND LIMITS TEMPERATURE RISE FOR HATTERAS/OCRACOKE ISLAND. HIGH CLOUDINESS SPILLING OVER THE RIDGE WILL INFILTRATE THE AREA AREA TODAY AND SHUD SEE SOME CUMULUS BUILDING LATE AS A THIN RIBBON OFF DEEPER MOISTURE APPROACHES. OVERALL PRECIP CHANCES ARE VERY LOW/SLIGHT CHC OVER THE AREA THRU TNGT DUE TO THE LIMITED AMOUNT OF AVAILABLE MOISTURE. HOWEVER MAY BEGIN TO SEE SOME ISOLD SHOWERS OR A TSTORM FIRE UP BY VERY LATE AFTN INTO THE EARLY EVE AS SFC BNDRY APPROACHES AND INTERACTS WITH SEABREEZE BNDRY. THOUGHT ABOUT REMOVING TSTMS ENTIRELY BUT DECIDED TO KEEP IT IN FOR THE EVE HOURS GIVEN SOME WEAK INSTABILITY AND FOR CONTINUITY PURPOSES. ANY ISOLD TSTMS WILL BE ENDING BY LATE EVE AS NOCTURNAL STABILITY SETS IN. RAINFALL AMOUNTS (IF ANY) WILL BE VERY LIGHT AS WELL. TEMPS TNGT WILL HAVE TIME TO DECLINE AFTER FRONTAL PASSAGE ESP OVR INLAND AREAS. LOWS RANGING FROM THE MID 60S INLAND TO LOW 70S COAST WHERE WIND OFF WARM WATER OFFSETS POST FRONTAL TEMPERATURE FALL. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... THE UPPER RIDGE WILL CONTINUE TO RETROGRADE TO THE SW THURSDAY WITH TROUGHING DEVELOPING AND DEEPENING OVER THE EASTERN US. SFC FRONT WIL STALL S OF THE AREA EARLY THU WITH WEAK HIGH PRES BUILDING INTO FROM THE NW. DECREASING THICKNESS PATTERN YIELDS HIGHS 5-10F DEGS COOLER THAN TODAY...ESPECIALLY NOTICABLE FOR NRN OBX. MUCH COOLER TEMPS WILL RESULT THU NIGHT WITH LOWS REACHING UPPER (PSBLY MID) 50S INLAND WITH MID TO UPPER 60S CLOSER TO THE COAST. && .LONG TERM /FRIDAY THROUGH TUESDAY/... ANTICIPATE SUBSIDENCE BEHIND THE COLD FRONT TO CONTINUE INTO FRIDAY WITH DRY CONDITIONS. UPPER LEVEL TROUGHING WILL SLOWLY MIGRATE OFF THE NEW ENGLAND COAST EARLY SATURDAY GIVING WAY TO MID/UPPER LEVEL RIDGING. THE REMNANTS OF TD HERMINE WILL BE INFLUENCED BY THE WESTERLIES AS IT TRAVELS NORTH THEN EAST THRU THE MSVLY AND INTO THE OHVLY FRIDAY AND FRIDAY NIGHT. REMNANTS WILL THEN GET ABSORBED INTO INCOMING COLD FRONT WHEN IT SEEMS THE BULK OF THE MOISTURE CROSSES THE AREA LATER IN THE WEEKEND. HAVE DELAYED ONSET OF ANY ASSOCD PCPN UNTIL SAT AFTN AND THIS MAY NEED TO BE PUSHED BACK EVEN FARTHER IF MODEL TRENDS HOLD. THE BEST CONVERGENCE/LIFT/MOISTURE WILL BE SUNDAY INTO SUNDAY NIGHT IN ASSOCIATION WITH THE FRONTAL BOUNDARY. LI VALUES SUGGEST THE POSSIBILITY FOR SOME CONVECTION SUNDAY INTO SUNDAY NIGHT. HAVE TRENDED A BIT QUICKER (AND LOWERED POPS) WITH PCPN ENDING EARLY NEXT WEEK AS PUSH OF DRIER NW FLOW ALOFT AND SFC HIGH PRES HAVE SPEEDED UP FROM PREVIOUS MODEL RUNS. TEMPERATURES WILL BE NOT DEVIANT TOO MUCH FROM SEASONABLE NORMALS THRU THE PERIOD. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... FOG DEVELOPMENT LIMITED EARLY THIS MORNING AS LIGHT SLY FLOW PERSISTS ACROSS RTES BRINGING SOME MIXING...ESPECIALLY ACROSS THE COASTAL PLAIN WHERE WINDS HAVE BEEN SLIGHTLY STRONGER. OAJ HAS BEEN THE ONLY TERMINAL SEEING PATCHY LIFR FOG SO FAR AND EXPECT THE BEST CHANCES FOR FOG THIS MORNING WILL BE AT OAJ AND EWN WHERE WINDS HAVE BEEN LIGHTER. ANY FOG REMAINING AT SUNRISE WILL QUICKLY DISSIPATE. A FRONT WILL APPROACH FROM THE NW TODAY BRINGING INCREASING HIGH CLOUDS AND STRENGTHENING SWLY FLOW WITH GUSTS TO AROUND 15 KT THIS AFTERNOON. VERY LIMITED MOISTURE ASSOC WITH THE FRONT AND EXPECT VFR CONDITIONS TO PERSIST TONIGHT WITH CIGS AOA 6KT AND ONLY A VERY SLIGHT CHANCE OF A SHOWER. THE COLD FRONT MOVES OFFSHORE EARLY FRI WITH HIGH PRES BUILDING INTO THE REGION AND VFR CONDITIONS DOMINATING FRI INTO SAT. AN UNSETTLED PERIOD POSSIBLE FOR THE SECOND HALF OF THE WEEKEND AS THE FRONT LIFTS BACK NORTH THROUGH THE AREA AS A WARM FRONT AS THE FLOW BECOMES SOUTHERLY AHEAD OF ANOTHER COLD FRONT WHICH WILL APPROACH FROM THE WEST ON SUNDAY. THE FRONT IS EXPECTED TO MOVE OFF THE COAST MONDAY MORNING. && .MARINE... SWLY FLOW WILL CONTINUE TO INCREASE ACROSS THE WATERS TODAY AHEAD OF A COLD FRONT APPROACHING FROM THE W. WINDS GENERALLY 10-15 KT THIS MORNING BUT WILL INCREASE TO 15 TO 20 KT DURING THE AFTERNOON THROUGH LATE TONIGHT. THE FRONT WILL CROSS THE WATERS AFTER MIDNIGHT WITH N/NWLY FLOW AROUND 10 KT FOR MUCH OF THU. ANOTHER WEAK TROUGH MOVES ACROSS THE REGION LATE THU AND EXPECT WINDS TO BRIEFLY SHIFT BACK TO S/SWLY LATE THU AFTN UNTIL LATE THU NIGHT. HIGH PRES BUILDING FROM THE W WILL BRING A N/NWLY SURGE AROUND 10-15 KT FRI MORNING...THEN WINDS GRADUALLY VEER TO SELY SAT AS THE HIGH MOVES OFFSHORE AND TO SWLY SUN AS A WARM FRONT LIFTS N OF THE REGION. A COLD FRONT WILL APPROACH THE WATERS SUN AND IS PROGGED TO CROSS THE WATERS LATE SUN NIGHT. SEAS AROUND 2 FT ACROSS THE WATERS THIS MORNING WILL GRADUALLY BUILD TODAY AS SWLY FLOW INCREASED. BOTH WAVEWATCH AND SWAN HAVE MAX SEAS AT 4 AND 5 FT RESPECTIVELY...SO SCA CONDITIONS ARE NOT ANTICIPATED AT THIS TIME. SEAS SUBSIDE TO 2-3 FT THU AND ARE EXPECTED TO REMAIN AOB 4FT THROUGH THE REST OF THE FORECAST PERIOD. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...BTC SHORT TERM...BTC LONG TERM...BTC/JME/LP AVIATION...SK MARINE...SK 000 FXUS62 KILM 080700 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 300 AM EDT WED SEP 8 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL TODAY. A COLD FRONT WILL MOVE ACROSS THE AREA TONIGHT INTO THURSDAY BUT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN. A TRANSITION TO A MORE HUMID AIR-MASS THIS WEEKEND WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY. WEAK HIGH PRESSURE WILL FOLLOW MONDAY AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM WEDNESDAY...SOUTHWEST FLOW WILL INCREASE TODAY AHEAD OF APPROACHING COLD FRONT...WHICH WILL SLOWLY MOVE ACROSS THE EASTERN CAROLINAS STARTING THIS EVENING...AND WILL BE MOSTLY OFFSHORE BY DAYBREAK THURSDAY. SOUTHWESTERLY FLOW WILL HELP BUILD THERMAL RIDGE JUST A TAD...ALLOWING TEMPERATURES TO RISE A BIT OVERALL FROM YESTERDAYS VALUES. THIS WILL BE ESPECIALLY TRUE ALONG THE COAST...WHERE ONSHORE FLOW HAS KEPT TEMPERATURES CONFINED TO THE 80S FOR THE PAST FEW DAYS. EXPECT MAXIMUM TEMPERATURES AROUND 90 FOR THE COASTAL COUNTIES...UPPER 80S RIGHT ALONG THE COAST...AND LOWER TO MID 90S INLAND. OVERNIGHT WILL SEE MINIMUM TEMPERATURES AROUND OR JUST ABOVE CLIMO AS COLD SURGE WILL BE WEAK. EXPECT LOWER 70S ALONG THE COAST...UPPER 60S INLAND. FRONT WILL BE RELATIVELY DRY WITH WITH MOISTURE CONCENTRATED TO THE NORTH AND EAST...SO EXPECT FRONT TO BE ACCOMPANIED BY ISOLATED TO WIDELY SCATTERED CONVECTION...MAINLY OVER OUR NC COASTAL COUNTIES...DURING THE EVENING AND OVERNIGHT HOURS. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...COLD FRONT MOVING ACROSS THE AREA AT THE START OF THE PERIOD MAY LEAD TO A FEW ISOLATED MORNING SHOWERS ALONG THE COAST THU. DEEP NORTHWESTERLY FLOW SETS UP BY MIDDAY AS 5H TROF AXIS PUSHES OFFSHORE. LARGE AMOUNT OF LOW AND MID LEVEL DRY AIR SPREADING OVER THE REGION WILL BRING AN END TO LINGERING SHOWERS AND CLOUDS. NORTHWEST FLOW AND AFTERNOON SUN SHOULD PUSH HIGHS ABOVE CLIMO THU. DRY AIR AND LIGHT NORTHERLY FLOW MAY ALLOW FOR SOME RADIATIONAL COOLING THU NIGHT BUT FAIR AMOUNT OF LOW LEVEL MOISTURE MAY LIMIT ITS EFFECTIVENESS. NOT GOING QUITE AS COOL AS GUIDANCE BUT DID TREND LOWS DOWN. STILL LACK CONFIDENCE IN THE FRI FORECAST BUT 00Z NAM/GFS/CANADIAN ARE IN GOOD AGREEMENT SHOWING REMAINS OF THE FRONT STALLED TO THE SOUTH AND A DRY FORECAST FRI AND FRI NIGHT. SOUNDINGS KEEP PWATS BELOW 1 INCH AND SHOW A LOT OF DRY AIR FROM THE SURFACE TO 300 MB. IN ADDITION TO ALL THE DRY AIR THERE ARE NO SIGNIFICANT UPPER LEVEL FEATURES. KEEPING POPS OUT FOR FRI AND FRI NIGHT. PLENTY OF SUN AND DOWNSLOPE FLOW WILL PUSH TEMPS A FEW DEGREES ABOVE CLIMO...THOUGH SEA BREEZE WILL KEEP COASTAL LOCATIONS A DEGREE OR TWO COOLER...FRI AFTERNOON. AIR MASS MODIFICATION AND SLIGHT INCREASE IN BOUNDARY LAYER MOISTURE/WINDS WILL KEEP TEMPS NEAR CLIMO FRI NIGHT. && .LONG TERM /SATURDAY THROUGH TUESDAY/... AS OF 3 PM WEDNESDAY...REMAINS OF BOUNDARY STALLED SOUTH OF THE AREA LIFT NORTH ON SAT. RETURN FLOW INCREASES LOW LEVEL MOISTURE SAT AND SAT NIGHT. AT THE SAME TIME THE REMAINS OF HERMINE SUPPLY SOME MOISTURE ALOFT AND A LITTLE LEFT OVER DYNAMICS AHEAD OF COLD FRONT SLATED TO CROSS THE AREA SUN NIGHT INTO MON. 00Z GFS/CANADIAN SUGGEST INCREASING PRECIP CHANCES SAT NIGHT INTO SUN WITH MORE OF A DRY FORECAST FOR SAT. 12Z ECMWF IS A LITTLE SLOWER THAN THE 00Z GUIDANCE AND SUGGESTS PRECIP LINGERING INTO MON. WILL GO WITH SLIGHT CHC SAT AND KEEP CHC SAT NIGHT THROUGH SUN NIGHT. NEXT AIR MASS BUILDS IN BEHIND THE FRONT MON AND TUE WITH DEEP DRY NORTHWEST FLOW SETTING UP AS 5H RIDGE TRIES TO BUILD OVER THE SOUTHERN US. TEMPERATURES NEAR TO SLIGHTLY ABOVE CLIMO. && .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/... AS OF 06Z...MODERATE CONFIDENCE THROUGH THE VALID PERIOD DUE TO POTENTIAL FOG OVERNIGHT. DIURNAL CU HAS ERODED OVER THE AREA...BUT CIRRUS SHIELD ASSOCIATED WITH COLD FRONT AND SOME HERMINE MOISTURE IS RAPIDLY APPROACHING FROM THE WEST. AT THE SAME TIME...WINDS HAVE NOT DECREASED AS RAPIDLY AS PREVIOUSLY ANTICIPATED...AND DEWPOINT DEPRESSIONS HAVE REMAINED HIGH. THE ADDITIONAL CLOUD COVER AND HIGHER WINDS WILL INHIBIT RADIATIONAL COOLING OVERNIGHT SO HAVE SLOWED ONSET OF FOG AND RAISED WORST VSBYS FROM PREVIOUS TAFS. WITH TD/S STILL AROUND 70...CANNOT RULE OUT FOG DEVELOPMENT OVERNIGHT...AND HAVE MVFR AT ALL TAF SITES. THE BEST CHANCE OF VSBY RESTRICTIONS WILL BE AT FLO/CRE...BUT WILL NOT BE ENTIRELY SURPRISED IF VSBYS REMAIN PREDOMINATELY UNRESTRICTED...AND MAY HAVE TO AMEND TOWARDS SUNRISE. AFTER SUNRISE FOG WILL RAPIDLY BURN OFF LEAVING ONLY A FEW CLOUDS THROUGH THE MORNING. WITH SUBSIDENCE THROUGH THE COLUMN AM NOT EXPECTING MUCH CU ON WEDNESDAY...BUT SCT VFR CU WILL LIKELY DEVELOP DURING THE AFTN. WINDS WILL BECOME SOUTHWESTERLY DURING WEDNESDAY...AND RANGE FROM LESS THAN 10 KTS INLAND...TO 8 TO 12 KTS AT THE COAST. AFTER NIGHTFALL...COLD FRONT WILL BEGIN TO APPROACH FROM THE WEST WHICH WILL INCREASE MID LEVEL CLOUD COVER ACROSS THE TERMINALS. WINDS WILL LIKELY REMAIN ELEVATED FROM THE SW AS WELL AS PRESSURE GRADIENT WILL TIGHTEN AHEAD OF FROPA. NOT ANTICIPATING ANY RAINFALL BEFORE THE END OF THIS VALID PERIOD HOWEVER. EXTENDED OUTLOOK...MORNING FOG POSSIBLE EACH MORNING. COLD FRONT WILL APPROACH THE AREA THURSDAY MORNING WITH A SLIGHT CHANCE OF SHOWERS. MORE SHOWERS ARE POSSIBLE FOR THE WKND WITH THE ADVANCE OF A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 AM WEDNESDAY...SOUTHWESTERLY FLOW WILL INCREASE TODAY AND TONIGHT AHEAD OF APPROACHING COLD FRONT...WHICH WILL SLOWLY MOVE ACROSS THE EASTERN CAROLINAS STARTING THIS EVENING...AND WILL BE OVER THE WATERS BY DAYBREAK THURSDAY. LIGHT WINDS THIS MORNING WILL INCREASE TO 10 TO 15 KTS THIS AFTERNOON AND AROUND 15 KTS OVERNIGHT SEAS WILL BUILD AS A RESULT...FROM PRESENT 1 TO 2 FT TO AROUND 2 FT THIS AFTERNOON AND 2 TO 4 FT OVERNIGHT. SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM WEDNESDAY...COLD FRONT MOVES ACROSS THE WATERS EARLY IN THE PERIOD BEFORE STALLING JUST SOUTH OF THE AREA. ILL DEFINED GRADIENT THROUGH THE PERIOD WILL RESULT IN LIGHT NORTHERLY FLOW AS HIGH BUILDS IN. WINDS WILL BECOME EAST TO SOUTHEAST EACH DAY AS THE SEA BREEZE DOMINATES THE LOW LEVEL WIND FIELD. SPEEDS IN THE 5 TO 10 KT RANGE FOR A MAJORITY OF THE PERIOD WHILE SEAS RUN 2 TO 3 FT. LONG TERM /SATURDAY THROUGH SUNDAY/... AS OF 3 AM WEDNESDAY...RELAXED GRADIENT ON SAT MEANS LOW LEVEL FLOW WILL CONTINUE TO BE DOMINATED BY MESO SCALE FEATURES...NAMELY THE SEA BREEZE. LIGHT NORTHEAST WINDS EARLY SAT WILL BECOME SOUTHEAST DURING THE DAY BUT REMAIN 10 KT OR LESS. SURFACE RIDGE AXIS SHIFTS OFFSHORE SAT NIGHT INTO SUN WITH FLOW BECOMING MORE SOUTH-SOUTHWEST. SPEEDS WILL REMAIN IN THE 10 KT RANGE THROUGH SAT NIGHT. SPEEDS PICK UP SUN/SUN NIGHT AS GRADIENT TIGHTENS A LITTLE AHEAD OF APPROACHING COLD FRONT. NOT EXPECTING MUCH MORE THAN 15 KT...THOUGH A FEW GUSTS TO 20 KT WILL BE POSSIBLE. SEAS WILL RUN 2 TO 3 FT SAT WITH A SLIGHT INCREASE...AROUND 3 FT WITH ISOLATED 4 FT POSSIBLE...SUN. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...REK SHORT TERM...III LONG TERM...III AVIATION...JDW 000 FXUS62 KRAH 080659 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 259 AM EDT WED SEP 8 2010 .SYNOPSIS... A WEAK COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA LATE TODAY AND WILL SETTLE SOUTH OF THE AREA OVERNIGHT. BEHIND THE FRONT... CANADIAN HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 241 AM WEDNESDAY... MID/UPPER LOW OVER THE GREAT LAKES WILL MOVE INTO SOUTHEASTERN CANADA TODAY... AND WILL REACH THE NEW ENGLAND AREA TONIGHT/THURSDAY MORNING. THE ASSOCIATED TRAILING COLD FRONT EXTENDING FROM THE LOWER GREAT LAKES SOUTHWEST INTO THE SOUTHERN PLAINS WILL MOVE INTO THE AREA LATE TODAY AND DURING THE EVENING HOURS. SATELLITE DERIVED BLENDED TOTAL PRECIP WATER IMAGERY ACTUALLY SHOWS VERY DEEP MOISTURE ON THE SOUTHERN PERIPHERY OF THE FRONT...WITH THE NORTHERN STREAM LOW AND UPPER TROUGH ACTUALLY TAPPING INTO SOME OF THE MID AND UPPER LEVEL TROPICAL MOISTURE PLUME ASSOCIATED WITH THE REMNANTS HERMINE. ALL MODELS SHOW PWATS INCREASING TO 2.0" AS THE FRONT BEGINS TO SPILL OVER THE MOUNTAINS. UNFORTUNATELY THIS HIGH MOISTURE CONTENT ATTENDANT TO THE FRONT WILL GO BY THE WAY SIDE...AND THE FRONT WILL NOT BE THE MUCH NEEDED RAIN PRODUCER THAT MUCH OF THE STATE NEEDS AS D1 DROUGHT CONDITIONS THREATEN TO EXPAND ACROSS THE AREA AS CENTRAL NC WILL REMAIN TOO FAR SOUTH AWAY FROM THE STRONG DYNAMICS (180 METER H5 HEIGHT FALLS) ACCOMPANYING THE NORTHERN STREAM LOW. ADDITIONALLY...ABUNDANT CLOUD COVER AND DELAYED EROSION OF MID-LEVEL CAP WILL KEEP THE LID ON THE INSTABILITY(500 TO 700 MLCAPE) WITH A STRONG LOW-LEVEL DOWNSLOPE COMPONENT RESULTING IN A VERY DRY SUB-CLOUD LAYER. ALTHOUGH RAIN CHANCES HAVE BEEN BUMPED TO A SLIGHT CHANCE...EXPECT ONLY A FEW HUNDREDTHS AT BEST AT A FEW SITES...WITH MOST LOCATIONS ONLY REPORTING TRACE AMOUNTS AS THE DRY SUB-LAYER WILL PRECLUDE SIGNIFICANT RAINFALL. THE TIMING OF THIS DEEP MOISTURE SPREADING INTO THE AREA FROM WEST TO EAST WILL IMPACT DAYTIME HIGHS GREATER IN THE WEST...WITH LESS IMPACTS IN THE EAST. HIGHS IN THE MID TO UPPER NORTHWEST TO LOWER 90S EAST. ALTHOUGH THE FRONT DOES NOT CLEAR THE AREA UNTIL 06Z THURSDAY...THE LOSS OF DAYTIME HEATING SHOULD SEND THE ALREADY DISMAL RAIN CHANCES TO NEAR ZERO. MODELS HAVE BEEN PERSISTENT WILL SHOWING STRONG DRYING BEHIND THE FRONT...WITH A SOUTHERN PUSH OF THE ELONGATED HIGH PRESSURE OVER SOUTHERN CANADA. MORNING COMMUTERS WILL BE GREETED BY MARKEDLY LESS HUMID AIR BY SUNRISE...ESPECIALLY IN THE WEST...WITH MODELS SHOWING SOME SOME 40 DEGREE DEWPOINT READINGS SURGING INTO THE AREA FROM THE WEST. LOWS IN THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. && .SHORT TERM/THURSDAY THROUGH FRIDAY NIGHT/... AS OF 241 AM WEDNESDAY... COLD FRONT WILL SETTLE SOUTH OF THE AREA BY THE START OF THURSDAY MORNING WITH CENTRAL NC UNDERNEATH WEAK HIGH FALLS ALOFT AS CLOSED LOW OVER NEW ENGLAND PUSHES SLOWLY OFF THE EAST COAST. BELOW NORMAL PWAT AIRMASS( 000 FXUS62 KMHX 080659 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 259 AM EDT WED SEP 8 2010 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL EXTEND SOUTHWEST INTO THE AREA THROUGH TONIGHT. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. WEAK HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY. A WARM FRONT WILL LIFT NORTH THROUGH THE REGION ON SATURDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST SUNDAY AND MOVE INTO THE AREA MONDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 845 PM TUESDAY...HIGH PRES WILL CONT TO EXTEND SW INTO THE REGION TONIGHT. LOOKS LIKE BEST GRDNT WILL BE INLAND AND N AND MAY SEE LOW TEMPS THESE REGION A BIT HIGHER THEN SRN CST WHERE WINDS WILL LIKELY GO CALM. LOWERED TEMPS A BIT OBX AND SRN CST OTHERWISE NO CHANGE WITH CLR SKIES INIT THEN POSS SOME THIN HIGH CLDS LATE. && .SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/... AS OF 245 PM TUESDAY...THE UPPER RIDGE WILL RETROGRADE TO THE SW WITH TROUGHING DEVELOPING OVER THE EASTERN US. THIS WILL ALLOW A WEAK COLD FRONT WITH LIMITED MOISTURE TO APPROACH THE AREA LATE WEDNESDAY AND CROSS THE REGION WEDNESDAY NIGHT. AHEAD OF THE FRONT SW FLOW WILL PRODUCE VERY WARM READINGS WITH HIGHS IN THE LOWER 90S EXPECTED...A LITTLE COOLER ALONG THE COAST SOUTH OF OREGON INLET WHERE THE SEA BREEZE WILL OCCUR. PREVIOUS SHIFT ADDED A SLIGHT CHANCE FOR RAIN AHEAD OF THE FRONT INLAND/CHANCE IMMEDIATE COAST FOR A SHOWER/THUNDERSTORM FROM 22Z-09Z WEDNESDAY/WEDNESDAY NIGHT AND WILL STAY WITH THIS THINKING WITH NEGATIVE LI`S AND DECENT LOW LEVEL CONVERGENCE FORECAST OVER EASTERN NC WEDNESDAY NIGHT. THE GFS WAS THE WETTEST OF THE 12Z MODELS WITH THIS FEATURE SO BLENDED THIS WITH THE DRIER ECMWF AND MIDDLE OF THE ROAD NAM. TEMPERATURES WILL COOL INTO THE MIDDLE 60S BEHIND THE FRONT WEDNESDAY NIGHT AND MIDDLE TO A FEW UPPER 80S THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 245 PM TUESDAY...ANTICIPATE SUBSIDENCE BEHIND THE COLD FRONT TO CONTINUE INTO FRIDAY WITH DRY CONDITIONS. UPPER LEVEL TROUGHING WILL SLOWLY MIGRATE OFF THE NEW ENGLAND COAST EARLY SATURDAY GIVING WAY TO MID/UPPER LEVEL RIDGING. THE REMNANTS OF TS HERMINE WILL BE INFLUENCED BY THE WESTERLIES AS IT TRAVELS NORTH INTO THE CENTRAL CONUS THURSDAY INTO FRIDAY. GFS/ECMWF BOTH HAVE THE VORT MAX ASSOCIATED WITH THIS SYSTEM CROSSING EASTERN NC EARLY SATURDAY AS IT GETS CAUGHT IN THE UPPER LEVEL TROUGH SET TO THE NORTH. HOWEVER...THE REMNANTS MAY GET INFUSED WITH A COLD FRONT MOVING ACROSS THE LEE SIDE OF THE ROCKIES FRIDAY. WILL NEED TO MONITOR THE TIMING ON THIS. REGARDLESS...IT SEEMS THE BULK OF THE MOISTURE WILL ACCOMPANY THE COLD FRONT AS IT APPROACHES THE AREA LATER IN THE WEEKEND. A WARM FRONT WILL INCREASE THE CHANCE OF PRECIPITATION SATURDAY...WHILE THE BEST CONVERGENCE/LIFT/MOISTURE WILL BE SUNDAY INTO EARLY MONDAY IN ASSOCIATION WITH THE FRONTAL BOUNDARY. LI VALUES SUGGEST THE POSSIBILITY FOR SOME CONVECTION SUNDAY INTO SUNDAY NIGHT. THEREFORE...HAVE MODIFIED THE FORECAST SLIGHTLY TO REFLECT THIS TREND. TEMPERATURES WILL BE NEAR SEASONABLE NORMALS WITH COOLEST READINGS OCCURRING THURSDAY NIGHT WHEN RADIATIONAL COOLING LEADS TO LOWS IN THE UPPER 50S INLAND. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... FOG DEVELOPMENT LIMITED EARLY THIS MORNING AS LIGHT SLY FLOW PERSISTS ACROSS RTES BRINGING SOME MIXING...ESPECIALLY ACROSS THE COASTAL PLAIN WHERE WINDS HAVE BEEN SLIGHTLY STRONGER. OAJ HAS BEEN THE ONLY TERMINAL SEEING PATCHY LIFR FOG SO FAR AND EXPECT THE BEST CHANCES FOR FOG THIS MORNING WILL BE AT OAJ AND EWN WHERE WINDS HAVE BEEN LIGHTER. ANY FOG REMAINING AT SUNRISE WILL QUICKLY DISSIPATE. A FRONT WILL APPROACH FROM THE NW TODAY BRINGING INCREASING HIGH CLOUDS AND STRENGTHENING SWLY FLOW WITH GUSTS TO AROUND 15 KT THIS AFTERNOON. VERY LIMITED MOISTURE ASSOC WITH THE FRONT AND EXPECT VFR CONDITIONS TO PERSIST TONIGHT WITH CIGS AOA 6KT AND ONLY A VERY SLIGHT CHANCE OF A SHOWER. THE COLD FRONT MOVES OFFSHORE EARLY FRI WITH HIGH PRES BUILDING INTO THE REGION AND VFR CONDITIONS DOMINATING FRI INTO SAT. AN UNSETTLED PERIOD POSSIBLE FOR THE SECOND HALF OF THE WEEKEND AS THE FRONT LIFTS BACK NORTH THROUGH THE AREA AS A WARM FRONT AS THE FLOW BECOMES SOUTHERLY AHEAD OF ANOTHER COLD FRONT WHICH WILL APPROACH FROM THE WEST ON SUNDAY. THE FRONT IS EXPECTED TO MOVE OFF THE COAST MONDAY MORNING. && .MARINE... SWLY FLOW WILL CONTINUE TO INCREASE ACROSS THE WATERS TODAY AHEAD OF A COLD FRONT APPROACHING FROM THE W. WINDS GENERALLY 10-15 KT THIS MORNING BUT WILL INCREASE TO 15 TO 20 KT DURING THE AFTERNOON THROUGH LATE TONIGHT. THE FRONT WILL CROSS THE WATERS AFTER MIDNIGHT WITH N/NWLY FLOW AROUND 10 KT FOR MUCH OF THU. ANOTHER WEAK TROUGH MOVES ACROSS THE REGION LATE THU AND EXPECT WINDS TO BRIEFLY SHIFT BACK TO S/SWLY LATE THU AFTN UNTIL LATE THU NIGHT. HIGH PRES BUILDING FROM THE W WILL BRING A N/NWLY SURGE AROUND 10-15 KT FRI MORNING...THEN WINDS GRADUALLY VEER TO SELY SAT AS THE HIGH MOVES OFFSHORE AND TO SWLY SUN AS A WARM FRONT LIFTS N OF THE REGION. A COLD FRONT WILL APPROACH THE WATERS SUN AND IS PROGGED TO CROSS THE WATERS LATE SUN NIGHT. SEAS AROUND 2 FT ACROSS THE WATERS THIS MORNING WILL GRADUALLY BUILD TODAY AS SWLY FLOW INCREASED. BOTH WAVEWATCH AND SWAN HAVE MAX SEAS AT 4 AND 5 FT RESPECTIVELY...SO SCA CONDITIONS ARE NOT ANTICIPATED AT THIS TIME. SEAS SUBSIDE TO 2-3 FT THU AND ARE EXPECTED TO REMAIN AOB 4FT THROUGH THE REST OF THE FORECAST PERIOD. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...RF SHORT TERM...JME LONG TERM...JME/LP AVIATION...SK MARINE...SK 000 FXUS62 KRAH 080642 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 241 AM EDT WED SEP 8 2010 .SYNOPSIS... A WEAK COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA LATE TODAY AND WILL SETTLE SOUTH OF THE AREA OVERNIGHT. BEHIND THE FRONT... CANADIAN HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 241 AM WEDNESDAY... MID/UPPER LOW OVER THE GREAT LAKES WILL MOVE INTO SOUTHEASTERN CANADA TODAY... AND WILL REACH THE NEW ENGLAND AREA TONIGHT/THURSDAY MORNING. THE ASSOCIATED TRAILING COLD FRONT EXTENDING FROM THE LOWER GREAT LAKES SOUTHWEST INTO THE SOUTHERN PLAINS WILL MOVE INTO THE AREA LATE TODAY AND DURING THE EVENING HOURS. SATELLITE DERIVED BLENDED TOTAL PRECIP WATER IMAGERY ACTUALLY SHOWS VERY DEEP MOISTURE ON THE SOUTHERN PERIPHERY OF THE FRONT...WITH THE NORTHERN STREAM LOW AND UPPER TROUGH ACTUALLY TAPPING INTO SOME OF THE MID AND UPPER LEVEL TROPICAL MOISTURE PLUME ASSOCIATED WITH THE REMNANTS HERMINE. ALL MODELS SHOW PWATS INCREASING TO 2.0" AS THE FRONT BEGINS TO SPILL OVER THE MOUNTAINS. UNFORTUNATELY THIS HIGH MOISTURE CONTENT ATTENDANT TO THE FRONT WILL GO BY THE WAY SIDE...AND THE FRONT WILL NOT BE THE MUCH NEEDED RAIN PRODUCER THAT MUCH OF THE STATE NEEDS AS D1 DROUGHT CONDITIONS THREATEN TO EXPAND ACROSS THE AREA AS CENTRAL NC WILL REMAIN TOO FAR SOUTH AWAY FROM THE STRONG DYNAMICS (180 METER H5 HEIGHT FALLS) ACCOMPANYING THE NORTHERN STREAM LOW. ADDITIONALLY...ABUNDANT CLOUD COVER AND DELAYED EROSION OF MID-LEVEL CAP WILL KEEP THE LID ON THE INSTABILITY(500 TO 700 MLCAPE) WITH A STRONG LOW-LEVEL DOWNSLOPE COMPONENT RESULTING IN A VERY DRY SUB-CLOUD LAYER. ALTHOUGH RAIN CHANCES HAVE BEEN BUMPED TO A SLIGHT CHANCE...EXPECT ONLY A FEW HUNDREDTHS AT BEST AT A FEW SITES...WITH MOST LOCATIONS ONLY REPORTING TRACE AMOUNTS AS THE DRY SUB-LAYER WILL PRECLUDE SIGNIFICANT RAINFALL. THE TIMING OF THIS DEEP MOISTURE SPREADING INTO THE AREA FROM WEST TO EAST WILL IMPACT DAYTIME HIGHS GREATER IN THE WEST...WITH LESS IMPACTS IN THE EAST. HIGHS IN THE MID TO UPPER NORTHWEST TO LOWER 90S EAST. ALTHOUGH THE FRONT DOES NOT CLEAR THE AREA UNTIL 06Z THURSDAY...THE LOSS OF DAYTIME HEATING SHOULD SEND THE ALREADY DISMAL RAIN CHANCES TO NEAR ZERO. MODELS HAVE BEEN PERSISTENT WILL SHOWING STRONG DRYING BEHIND THE FRONT...WITH A SOUTHERN PUSH OF THE ELONGATED HIGH PRESSURE OVER SOUTHERN CANADA. MORNING COMMUTERS WILL BE GREETED BY MARKEDLY LESS HUMID AIR BY SUNRISE...ESPECIALLY IN THE WEST...WITH MODELS SHOWING SOME SOME 40 DEGREE DEWPOINT READINGS SURGING INTO THE AREA FROM THE WEST. LOWS IN THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. .SHORT TERM/THURSDAY THROUGH FRIDAY/... AS OF 241 AM WEDNESDAY... COLD FRONT WILL SETTLE SOUTH OF THE AREA BY THE START OF THURSDAY MORNING WITH CENTRAL NC UNDERNEATH WEAK HIGH FALLS ALOFT AS CLOSED LOW OVER NEW ENGLAND PUSHES SLOWLY OFF THE EAST COAST. BELOW NORMAL PWAT AIRMASS( 000 FXUS62 KRAH 080536 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 136 AM EDT WED SEP 8 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TONIGHT. A WEAK COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA LATE WEDNESDAY THROUGH WEDNESDAY NIGHT. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THURSDAY INTO FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... AS OF 925 PM... A LOW PRESSURE SYSTEM IN SOUTHERN CANADA WILL ADVANCE TOWARD THE COAST TONIGHT AND WEDNESDAY. A WEAK ASSOCIATED TROUGH WILL MOVE INTO NORTH CAROLINA TONIGHT...AND INTENSIFY SLIGHTLY LEE OF THE MOUNTAINS TOWARD SUNRISE. WEST TO NORTHWEST FLOW AT 850 AND 700 MILLIBARS WILL BE OF NO HELP IN TRANSPORTING MOISTURE OR DEVELOPING CONVERGENCE WHICH MIGHT AID UPDRAFTS. WITH AN INVERTED VEE BOUNDARY LAYER FORECAST TO TOP OUT ABOVE 6000 FEET WEDNESDAY AFTERNOON... WIDESPREAD MEASURABLE RAIN LOOKS DIFFICULT. MANY HOWEVER COULD SEE RAIN... BUT NOT MANY WILL MEASURE. HAVING BEEN SO NEGATIVE ABOUT RAIN... WILL HOWEVER LIFT RAIN CHANCES TO SLIGHT CHANCE ACROSS THE NORTHERN HALF OF CENTRAL NORTH CAROLINA FOR WEDNESDAY AFTERNOON DUE TO FAVORABLE SPEED AND DIRECTIONAL CONVERGENCE BELOW 850 MILLIBARS ON THE GEM AND MESO NAM MODELS AND REASONABLE MOISTURE ABOVE 10000 FEET. AMOUNTS MORE THAN A FEW HUNDREDTHS OF AN INCH WOULD BE A SURPRISE AND COVERAGE WILL BE LIMITED. RAIN CHANCES SLIP TO THE SOUTHEAST TOWARD SUNSET BUT WITH LOSS OF HEATING... WILL LIMIT ANY MEASURABLE RAIN TO ISOLATED... AND ENDING WELL BEFORE MIDNIGHT. POTENTIAL FOR STRATUS TONIGHT APPEARS WEAK. SOME WARM ADVECTION IN THE LOWEST FEW THOUSAND FEET FOR LIFT BUT MOISTURE IN THIS LAYER SHOULD BE DIMINISHED FROM THE PAST COUPLE OF NIGHTS. WOULD LIKE TO SEE 1000 TO 850 MILLIBAR MOISTURE ABOVE 85 PERCENT IN THE MODELS FOR SUNRISE WEDNESDAY AND IT IS GENERALLY WELL UNDER 70 PERCENT. ANY LOW STRATUS OR FOG LATE TONIGHT SHOULD BE PATCHY AND NOT PERSIST DEEP INTO THE MORNING AS HAS BEEN THE CASE RECENTLY. WITH INCREASING MOISTURE AT THE JET LEVEL AND SOME CIRRUS... RADIATIONAL COOLING LATE TONIGHT WILL BE LESSENED. LOW LEVEL THICKNESSES FORECAST UP ABOUT TEN METERS... WHICH IS GOOD FOR ABOUT THREE DEGREES ON ITS OWN. CURRENT FORECAST OF MOSTLY UPPER 60S FOR LOW TEMPERATURES TONIGHT ACCEPTED. CLOUDS WILL INHIBIT AFTERNOON TEMPERATURES A BIT IN THE NORTH WEDNESDAY. HIGH TEMPERATURES UPPER 80S NORTHWEST TO AROUND 93 SOUTHEAST HALF. WITH THE FRONT PASSING THOUGH WEDNESDAY NIGHT... WINDS SHIFT TO NORTH NORTHWEST... AND A THICKNESS GRADIENT OF PERHAPS EIGHTEEN METERS ACROSS THE AREA SUGGESTS AN EIGHT DEGREES SPREAD IN LOW TEMPERATURES THURSDAY MORNING... NORTH TO SOUTH... AT 60 TO 68. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 245 PM TUESDAY... THURSDAY INTO THURSDAY NIGHT...IN WAKE OF EXITING SURFACE FRONT WINDS WILL VEER TO THE NORTHWEST AND ADVECT SLIGHTLY COOLER DRIER AIR INTO CENTRAL NORTH CAROLINA. LOW LEVEL THICKNESSES FAIRLY CLOSE TO NORMAL FOR EARLY SEPTEMBER AND MOS GUIDANCE CORRESPOND FAIRLY WELL TO THESE LEVELS. THUS HAVE LOWERED MAXIMUM TEMPERATURES ABOUT 3 DEGREES FROM PREVIOUS FORECAST. (MAXIMUM TEMPERATURES 85 FAR NORTH TO 89 SOUTHWEST).CAVEAT TO FORECAST WILL BE THE POTENTIAL FOR OROGRAPHIC HIGH CLOUDS TO OCCUR...ESPECIALLY OVER THE SOUTHWEST HALF OF THE FORECAST AREA. PARAMETERS APPEAR TO BE IN PLACE WITH A STABLE AIR MASS ALOFT...AN UPPER LEVEL MOISTURE SOURCE OVER THE OHIO VALLEY AND MID AND UPPER LEVEL WINDS OF SUFFICIENT STRENGTH AND ORIENTATION. GFS RELATIVE HUMIDITY CROSS SECTIONS APPEAR TO PICK UP ON THIS SCENARIO. IF CIRRUS SHIELD THICK ENOUGH...THEN MAXIMUM TEMPERATURES ACROSS THE SOUTHWEST COUNTIES MAY END UP BEING A COUPLE OF DEGREES COOLER THAN FORECAST. MAY SEE SOME THINNING OF CIRRUS SHIELD THU NIGHT. HOWEVER ENOUGH MOISTURE MAY REMAIN TO KEEP SOME CLOUDS OVER THE SOUTHERN COUNTIES. THIS SHOULD LEAD TO MINIMUM TEMPERATURES BEING A COUPLE OF DEGREES WARMER THAN PREVIOUSLY FORECAST. EXPECT MAINLY CLEAR SKIES AND A LIGHT TO CALM WIND REGIME ACROSS THE NORTHEAST UNDERNEATH THE SURFACE RIDGE. THIS SHOULD SUPPORT COOLER MINIMUM TEMPERATURES. MINIMUM TEMPERATURES MID 50S FAR NORTHEAST TO MID 60S SOUTH AND SOUTHWEST. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 246 PM TUESDAY... UPPER AIR PATTERN THROUGH THE PERIOD WILL BE CHARACTERIZED BY A BROAD UPPER LEVEL RIDGE STRETCHING WEST TO EAST ACROSS TEXAS AND THE GULF WHILE THE MAIN BAND OF WESTERLIES WILL EXTEND FROM THE PACIFIC NORTHWEST THROUGH THE NORTHERN PLAINS AND GREAT LAKES TO SOUTHERN NEW ENGLAND. THIS TYPE OF PATTERN FOR CENTRAL NORTH CAROLINA USUALLY SPELLS DRY WEATHER WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. MODEL GUIDANCE IN GENERALLY GOOD AGREEMENT WITH SOME TIMING ISSUES BEYOND SATURDAY. FRIDAY INTO SATURDAY...WESTERLY LOW-MID LEVEL FLOW GRADUALLY BACKS IN RESPONSE TO AN APPROACHING MID LEVEL SHORT WAVE FROM THE WEST (REMNANTS OF HERMINE) AND A VORTICITY AXIS SWINGING AROUND THE BASE OF UPPER LOW OVER THE GULF OF MAINE AND NOVA SCOTIA. DEEP WEST FLOW AHEAD OF THESE FEATURES SHOULD INITIALLY LIMIT MOISTURE INFLUX. PLUS FLOW FAIRLY DIVERGENT ACROSS THE REGION LATE FRIDAY INTO EARLY SATURDAY. REMOVED SLIGHT CHANCE POP FOR LATE FRIDAY INTO FRIDAY EVENING BASED ON THIS SCENARIO. MAINTAINED A SLIGHT CHANCE POP ACROSS THE REGION SATURDAY AS MOISTURE SLOWLY INCREASES. GFS WETTER AND SLIGHTLY FASTER THAN ECMWF. IF THIS TIMING IS CORRECT...THEN COULD SEE SCATTERED SHOWERS ACROSS CENTRAL NORTH CAROLINA SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. ECMWF ABOUT 12 HOURS SLOWER WITH ITS MID LEVEL TROUGH AND DEEPEST MOISTURE ACROSS THE FORECAST AREA SATURDAY NIGHT INTO SUNDAY. FOR NOW WILL LEAN TOWARD THE SLOWER ECMWF SOLUTION. INCREASE IN CLOUDINESS SATURDAY INTO SUNDAY (ESPECIALLY SUNDAY) WILL RESULT IN A SHADING OF MAXIMUM TEMPERATURES FROM EARLIER FORECAST WHILE RAISING MINIMUM TEMPERATURES UP A COUPLE OF DEGREES. WILL PLACE THE HIGHEST POPS FOR THIS FORECAST PERIOD ON SUNDAY AND SUNDAY EVENING TO COINCIDE WITH PASSAGE OF LOW AND MID LEVEL TROUGH AND DEEPEST MOISTURE. MONDAY INTO TUESDAY WILL FEATURE AN IMPROVING WEATHER PATTERN. LOW AND MID LEVEL TROUGH SHOULD EXIT THE REGION BY EARLY MONDAY. SURFACE HIGH TO THE NORTH TO NORTHWEST WILL RESULT IN AN EAST FLOW. THIS FETCH OFF THE ATLANTIC MAY MAINTAIN LOW LEVEL MOISTURE RESULTING IN A SCATTERED AND POSSIBLY BROKEN STRATOCUMULUS FIELD. SURFACE RIDGE BECOMES MORE FIRMLY ENTRENCHED OVER THE REGION TUESDAY RESULTING IN FEWER CLOUDS. TEMPERATURES THROUGH PERIOD NEAR TO SLIGHTLY WARMER THAN NORMAL. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... AS OF 130 AM WEDNESDAY... GENERALLY VFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE CURRENT TAF PERIOD...HOWEVER PATCHY IFR/MVFR CEILINGS WILL BE POSSIBLE BETWEEN 08Z AND 13Z THIS MORNING. THE BEST CHANCE FOR THESE LOWER CEILINGS WILL OCCUR ACROSS THE EASTERN HALF OF THE FORECAST AREA WHERE SOME WARM AIR ADVECTION WILL OCCUR AHEAD OF AN APPROACHING COLD FRONT. ANY LOW CLOUDS THAT DEVELOP ARE EXPECTED TO MIX OUT QUICKLY AS SOUTHWESTERLY TO WESTERLY SURFACE FLOW INCREASES AHEAD OF THE COLD FRONT. A FEW SPRINKLES OR SHOWERS WILL BE POSSIBLE JUST AHEAD OF THE FRONT THIS AFTERNOON...BUT CHANCES/COVERAGE ARE TOO LOW TO INCLUDE MENTION IN THE TAFS FOR NOW. THE FRONT SHOULD MOVE THROUGH THE AREA AFTER SUNSET...SHIFTING THE WINDS TO THE NORTHWEST AND GRADUALLY CLEARING OUT THE SKIES. THEN...VFR CONDITIONS WILL PERSIST THROUGH FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. MVFR CEILINGS ARE POSSIBLE LATE FRIDAY NIGHT INTO SATURDAY AS THE FRONT TO OUR SOUTH TRIES TO HEAD BACK NORTH AS A WARM FRONT. A FEW SHOWERS OR STORMS ARE POSSIBLE SATURDAY INTO SUNDAY AS WE GET INTO THE WARM SECTOR AND DESTABILIZE. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...WSS LONG TERM...WSS AVIATION...KRR/VINCENT 000 FXUS62 KILM 080155 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 955 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH WEDNESDAY. THE ARRIVAL OF A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN. A TRANSITION TO A MORE HUMID AIR-MASS THIS WEEKEND WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY. WEAK HIGH PRESSURE WILL FOLLOW MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 9 PM TUESDAY...RIDGING ALOFT AND AN EAST-TO-WEST ORIENTED SURFACE RIDGE WILL KEEP BENIGN WEATHER IN PLACE TONIGHT. DAYTIME CUMULUS AND ISOLATED INLAND SHOWERS HAVE DISSIPATED. CLEAR SKIES ARE ANTICIPATED THROUGH MIDNIGHT...AT WHICH TIME CIRRUS SPILLING OVER THE UPPER RIDGE TO OUR WEST MAY TURN SKIES PARTLY CLOUDY...ESPECIALLY ALONG AND WEST OF I-95. AS THE SURFACE RIDGE PUSHES NORTH OF THE AREA SYNOPTIC WIND DIRECTIONS WILL TURN FROM SOUTHEASTERLY TO SOUTHWESTERLY LATE...ALBEIT WITH VERY LIGHT SPEEDS EXPECTED. THE BOUNDARY LAYER SHOULD DECOUPLE IN MOST SPOTS WITH PATCHY FOG DEVELOPING DUE TO SEASONABLY RICH LOW LEVEL MOISTURE. LITTLE CHANGE HAS BEEN MADE TO FORECAST LOWS TONIGHT...RANGING FROM THE MID 60S INLAND TO AROUND 70 ON THE BEACHES. IT IS INTERESTING TO NOTE THAT HOURLY TEMPERATURES WILL FOLLOW VERY DIFFERENT CURVES AT DIFFERENT POINTS IN THE AREA OVERNIGHT: A CLASSIC DIURNAL CURVE IS EXPECTED INLAND...BUT ALONG THE BEACHES TEMPERATURES WILL HOLD STEADY AROUND 80 UNTIL THE ONSHORE FLOW ENDS AFTER MIDNIGHT AT WHICH POINT TEMPERATURES WILL PLUMMET TO NEAR FORECAST LOWS RATHER QUICKLY. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS MIDDLE AMERICA...A TROUGH WILL HAVE A TENDENCY TO DIG ALONG THE ATLANTIC COAST. THIS MAY WELL BE SUFFICIENT ENOUGH TO ALLOW A COLD FRONT TO REACH THE CAROLINAS WED NIGHT. SOME OF THE MOISTURE FROM FORMER TROPICAL STORM HERMINE MAY BEGIN TO GET ENTRAINED WITHIN THIS FRONTAL ZONE AS IT MOVES FURTHER S WED NIGHT AND THU. STILL LOOKS LIKE ONLY A SMALL CHANCE FOR MEASURABLE RAIN. THE SMALL CHANCES FOR CONVECTION SHOULD CONTINUE INTO THU...PRIMARILY ALONG THE COAST...AS THE COLD FRONT HANGS UP AND LOW LEVEL CONVERGENCE DEVELOPS ALONG THE SEABREEZE BOUNDARY. AT THIS TIME...NO SIGNIFICANT RAIN IS EXPECTED AS THERE IS JUST SO MUCH DRY AIR TO OVERCOME. OUR STRING OF DRY DAYS STANDS AT ABOUT 2 WEEKS AND COUNTING FOR ALMOST ALL OF US. A DRY AND SLIGHTLY COOLER AIRMASS SHOULD GET REINFORCED LATE THU NIGHT. MAXIMUMS ON WED WILL BE HIGHER THAN ON THU...BUT BOTH DAYS WILL BE ABOVE NORMAL...EXCEPT ALONG THE COAST ON THU WHEN TEMPS WILL BE ABOUT NORMAL. DID NOT GO AS HIGH AS SOME OF THE MODEL OUTPUT FOR WED AS DO EXPECT CLOUDS TO BE ON THE INCREASE WITH THE APPROACH OF PEAK HEATING. SEABREEZE WILL MAKE BETTER INLAND PROGRESS THU THAN ON WED. A NOTICEABLE DROP IN DEWPOINTS IS EXPECTED ON THU...ESPECIALLY AWAY FROM THE COAST. DEWPOINTS MAY DROP TO THE MID AND UPPER 50S WITH A FEW SPOTS AS LOW AS THE LOWER 50S FROM KMEB TO KLBT TO KEYF TO WATHA. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...CONFIDENCE IS LOW FOR THIS EXTENDED FORECAST... ESPECIALLY REGARDING POTENTIAL UNSETTLED WX DURING THE WEEKEND. GFS AND ECMWF BOTH BRING THE REMNANT MOISTURE PLUME OF HERMINE ALL THE WAY OVER THE TOP OF THE UPPER RIDGE...AND ACROSS THE VIRGINIAS AND/OR THE CAROLINAS. GFS BRINGS THIS FEATURE THROUGH ON SATURDAY...WITH A COLD FRONT TO FOLLOW ON SUNDAY NIGHT. ECMWF IS NOTICEABLY SLOWER. BOTTOM LINE IS THAT CHANCE POPS ARE JUSTIFIED SAT THROUGH SUN NIGHT...WITH THINGS DRYING OUT EARLY NEXT WEEK. TEMPS WILL RUN ABOVE NORMAL THRU THE WEEKEND... ESPECIALLY BY NIGHT DUE TO CLOUDS AND TROPICAL MOISTURE...THEN BACK NEAR CLIMO MON-TUE. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...MODERATE CONFIDENCE THROUGH THE VALID PERIOD DUE TO POTENTIAL FOG OVERNIGHT. DIURNAL CU WILL RAPIDLY DISSIPATE THIS EVE LEAVING SKC OVER THE TERMINALS. WITH TD/S IN THE MID 60S TO LOW 70S...AND WINDS EXPECTED TO BECOME NEAR CALM...ANOTHER CHALLENGING FOG FORECAST EXISTS FOR OVERNIGHT. THERE ARE TWO SIGNIFICANT DIFFERENCES BETWEEN LAST NIGHT AND TONIGHT WHICH PLAY INTO THE FOG POTENTIAL. THE LLJ WHICH DEVELOPED JUST ABOVE THE B/L LAST NIGHT WILL NOT FORM TONIGHT...AND THE LAYER OF MOISTURE IN THE COLUMN IS MUCH MORE SHALLOW THAN IT WAS ON MONDAY NIGHT. THE MISSING LLJ SHOULD ELIMINATE MUCH STRATUS OVERNIGHT SO MORE RADIATIONAL COOLING IS LIKELY...BUT THE SHALLOW MOISTURE LAYER WILL NOT PERMIT DENSE FOG. CROSSOVER TEMPS WILL LIKELY NOT BE MET...AND MOISTURE ADVECTION WILL NOT BE AS PRONOUNCED AS LAST NIGHT EITHER. ALL OF THIS TOGETHER LEADS TO A FORECAST OF MVFR FOG...WITH THE BEST CHANCES BEING AT FLO/CRE. WITH A LIGHT SW WIND FORECAST TO DEVELOP...CRE MAY HAVE THE WORST VSBYS OVERNIGHT DUE TO LOCAL EFFECTS. WILL HAVE TO MONITOR CHANGING CONDITIONS AND UPDATE WITH 06Z ISSUANCE. AFTER SUNRISE FOG WILL RAPIDLY BURN OFF LEAVING ONLY A FEW CLOUDS THROUGH THE MORNING. WITH SUBSIDENCE THROUGH THE COLUMN AM NOT EXPECTING MUCH CU ON WEDNESDAY...BUT SCT VFR CU WILL LIKELY DEVELOP DURING THE AFTN. WINDS WILL BECOME SOUTHWESTERLY DURING WEDNESDAY...AND RANGE FROM LESS THAN 10 KTS INLAND...TO 8 TO 12 KTS AT THE COAST. EXTENDED OUTLOOK...MORNING FOG POSSIBLE EACH MORNING. COLD FRONT WILL APPROACH THE AREA THURSDAY MORNING WITH A SLIGHT CHANCE OF SHOWERS. MORE SHOWERS ARE POSSIBLE FOR THE WKND WITH THE ADVANCE OF A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM TUESDAY...THE CAROLINAS ARE CAUGHT IN A ZONE OF WEAK RIDGING EXTENDING BETWEEN HIGH PRESSURE NEAR BERMUDA AND A HIGH CENTERED OVER IOWA. THIS WILL LEAD TO LIGHT WINDS OVERNIGHT GENERALLY FROM THE SOUTHEAST AND SOUTH. THE AFTERNOON SEABREEZE PUSHED WIND SPEEDS AS HIGH AS 12-15 KT IN GUSTS. SPEEDS SHOULD SETTLE DOWN OVERNIGHT TO 8-10 KNOTS. RADAR SHOWS SOME LIGHT SHOWERS OUT BEYOND 50-60 MILES FROM SHORE. THESE SHOULD REMAIN OFFSHORE THROUGH THE NIGHT. SEAS ARE GENERALLY AROUND 2 FT IN A MIX OF 8-9 SECOND SWELL AND LOCAL WIND WAVES. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...WINDS WILL BE FROM THE SW AHEAD OF A COLD FRONT WHICH IS EXPECTED TO MOVE ACROSS THE WATERS LATE WED NIGHT. WINDS WILL SHIFT TO NW LATE WED NIGHT AND N TO NE THU MORNING. THE SEABREEZE CIRCULATION WILL BE THE PRIMARY DRIVER OF WIND DIRECTION WED AFTERNOON AND WINDS WILL BECOME SE TO S. THE FRONT WILL BE REINFORCED AND WITH THAT WINDS WILL VEER ALL THE WAY AROUND TO NNW LATE THU NIGHT. STRONGEST WINDS THIS PERIOD ARE EXPECTED TO OCCUR WED AFTERNOON AND EVE AHEAD OF THE FRONT. AT THIS TIME...THE NORTHERLY SURGE BEHIND THE FRONT IS EXPECTED TO BE BRIEF AND WEAK. HIGHEST SEAS THIS PERIOD ARE EXPECTED TO OCCUR WED NIGHT. WINDS AND SEAS WILL REMAIN BELOW EXERCISE CAUTION CRITERIA THROUGH THE PERIOD. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...GENERAL EASTERLY COMPONENT WILL PREVAIL FRI-SAT WITH WEAK HIGH PRESSURE TO OUR NORTH. LOOK FOR A SEABREEZE-DRIVEN OSCILLATION FROM N-NE EACH MORNING...TO SE EACH AFTERNOON. SPEEDS GENERALLY 10 KT OR LESS. EXPECT VEERING WINDS SAT NIGHT...THEN PICKING UP OUT OF THE SW ON SUNDAY AHEAD OF AN APPROACHING COLD FRONT. WILL BE WELL SHORT OF ADVISORY THRESHOLDS AS 15 KT/4 FT APPEARS TO BE THE WORST-CASE. && .TIDES... THE OCCURRENCE OF THE NEW MOON ON WED WILL PRODUCE HIGH ASTRONOMICAL TIDES THROUGH MID WEEK. HIGH TIDES WILL BE RIGHT AROUND ACTION STAGE...A HALF FOOT BELOW MINOR FLOOD STAGE...BUT GIVEN THERE WILL BE NO STRONG ONSHORE WINDS WE SHOULD REMAIN BELOW MINOR COASTAL FLOOD THRESHOLDS. HIGH TIDES ON WED ARE AROUND 8 AM AND 8 PM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...TRA SHORT TERM...RJD LONG TERM...RAS AVIATION...JDW TIDES...RJD 000 FXUS62 KRAH 080127 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 927 PM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TONIGHT. A WEAK COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA LATE WEDNESDAY THROUGH WEDNESDAY NIGHT. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THURSDAY INTO FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... AS OF 925 PM... A LOW PRESSURE SYSTEM IN SOUTHERN CANADA WILL ADVANCE TOWARD THE COAST TONIGHT AND WEDNESDAY. A WEAK ASSOCIATED TROUGH WILL MOVE INTO NORTH CAROLINA TONIGHT...AND INTENSIFY SLIGHTLY LEE OF THE MOUNTAINS TOWARD SUNRISE. WEST TO NORTHWEST FLOW AT 850 AND 700 MILLIBARS WILL BE OF NO HELP IN TRANSPORTING MOISTURE OR DEVELOPING CONVERGENCE WHICH MIGHT AID UPDRAFTS. WITH AN INVERTED VEE BOUNDARY LAYER FORECAST TO TOP OUT ABOVE 6000 FEET WEDNESDAY AFTERNOON... WIDESPREAD MEASURABLE RAIN LOOKS DIFFICULT. MANY HOWEVER COULD SEE RAIN... BUT NOT MANY WILL MEASURE. HAVING BEEN SO NEGATIVE ABOUT RAIN... WILL HOWEVER LIFT RAIN CHANCES TO SLIGHT CHANCE ACROSS THE NORTHERN HALF OF CENTRAL NORTH CAROLINA FOR WEDNESDAY AFTERNOON DUE TO FAVORABLE SPEED AND DIRECTIONAL CONVERGENCE BELOW 850 MILLIBARS ON THE GEM AND MESO NAM MODELS AND REASONABLE MOISTURE ABOVE 10000 FEET. AMOUNTS MORE THAN A FEW HUNDREDTHS OF AN INCH WOULD BE A SURPRISE AND COVERAGE WILL BE LIMITED. RAIN CHANCES SLIP TO THE SOUTHEAST TOWARD SUNSET BUT WITH LOSS OF HEATING... WILL LIMIT ANY MEASURABLE RAIN TO ISOLATED... AND ENDING WELL BEFORE MIDNIGHT. POTENTIAL FOR STRATUS TONIGHT APPEARS WEAK. SOME WARM ADVECTION IN THE LOWEST FEW THOUSAND FEET FOR LIFT BUT MOISTURE IN THIS LAYER SHOULD BE DIMINISHED FROM THE PAST COUPLE OF NIGHTS. WOULD LIKE TO SEE 1000 TO 850 MILLIBAR MOISTURE ABOVE 85 PERCENT IN THE MODELS FOR SUNRISE WEDNESDAY AND IT IS GENERALLY WELL UNDER 70 PERCENT. ANY LOW STRATUS OR FOG LATE TONIGHT SHOULD BE PATCHY AND NOT PERSIST DEEP INTO THE MORNING AS HAS BEEN THE CASE RECENTLY. WITH INCREASING MOISTURE AT THE JET LEVEL AND SOME CIRRUS... RADIATIONAL COOLING LATE TONIGHT WILL BE LESSENED. LOW LEVEL THICKNESSES FORECAST UP ABOUT TEN METERS... WHICH IS GOOD FOR ABOUT THREE DEGREES ON ITS OWN. CURRENT FORECAST OF MOSTLY UPPER 60S FOR LOW TEMPERATURES TONIGHT ACCEPTED. CLOUDS WILL INHIBIT AFTERNOON TEMPERATURES A BIT IN THE NORTH WEDNESDAY. HIGH TEMPERATURES UPPER 80S NORTHWEST TO AROUND 93 SOUTHEAST HALF. WITH THE FRONT PASSING THOUGH WEDNESDAY NIGHT... WINDS SHIFT TO NORTH NORTHWEST... AND A THICKNESS GRADIENT OF PERHAPS EIGHTEEN METERS ACROSS THE AREA SUGGESTS AN EIGHT DEGREES SPREAD IN LOW TEMPERATURES THURSDAY MORNING... NORTH TO SOUTH... AT 60 TO 68. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 245 PM TUESDAY... THURSDAY INTO THURSDAY NIGHT...IN WAKE OF EXITING SURFACE FRONT WINDS WILL VEER TO THE NORTHWEST AND ADVECT SLIGHTLY COOLER DRIER AIR INTO CENTRAL NORTH CAROLINA. LOW LEVEL THICKNESSES FAIRLY CLOSE TO NORMAL FOR EARLY SEPTEMBER AND MOS GUIDANCE CORRESPOND FAIRLY WELL TO THESE LEVELS. THUS HAVE LOWERED MAXIMUM TEMPERATURES ABOUT 3 DEGREES FROM PREVIOUS FORECAST. (MAXIMUM TEMPERATURES 85 FAR NORTH TO 89 SOUTHWEST).CAVEAT TO FORECAST WILL BE THE POTENTIAL FOR OROGRAPHIC HIGH CLOUDS TO OCCUR...ESPECIALLY OVER THE SOUTHWEST HALF OF THE FORECAST AREA. PARAMETERS APPEAR TO BE IN PLACE WITH A STABLE AIR MASS ALOFT...AN UPPER LEVEL MOISTURE SOURCE OVER THE OHIO VALLEY AND MID AND UPPER LEVEL WINDS OF SUFFICIENT STRENGTH AND ORIENTATION. GFS RELATIVE HUMIDITY CROSS SECTIONS APPEAR TO PICK UP ON THIS SCENARIO. IF CIRRUS SHIELD THICK ENOUGH...THEN MAXIMUM TEMPERATURES ACROSS THE SOUTHWEST COUNTIES MAY END UP BEING A COUPLE OF DEGREES COOLER THAN FORECAST. MAY SEE SOME THINNING OF CIRRUS SHIELD THU NIGHT. HOWEVER ENOUGH MOISTURE MAY REMAIN TO KEEP SOME CLOUDS OVER THE SOUTHERN COUNTIES. THIS SHOULD LEAD TO MINIMUM TEMPERATURES BEING A COUPLE OF DEGREES WARMER THAN PREVIOUSLY FORECAST. EXPECT MAINLY CLEAR SKIES AND A LIGHT TO CALM WIND REGIME ACROSS THE NORTHEAST UNDERNEATH THE SURFACE RIDGE. THIS SHOULD SUPPORT COOLER MINIMUM TEMPERATURES. MINIMUM TEMPERATURES MID 50S FAR NORTHEAST TO MID 60S SOUTH AND SOUTHWEST. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 246 PM TUESDAY... UPPER AIR PATTERN THROUGH THE PERIOD WILL BE CHARACTERIZED BY A BROAD UPPER LEVEL RIDGE STRETCHING WEST TO EAST ACROSS TEXAS AND THE GULF WHILE THE MAIN BAND OF WESTERLIES WILL EXTEND FROM THE PACIFIC NORTHWEST THROUGH THE NORTHERN PLAINS AND GREAT LAKES TO SOUTHERN NEW ENGLAND. THIS TYPE OF PATTERN FOR CENTRAL NORTH CAROLINA USUALLY SPELLS DRY WEATHER WITH SLIGHTLY ABOVE NORMAL TEMPERATURES. MODEL GUIDANCE IN GENERALLY GOOD AGREEMENT WITH SOME TIMING ISSUES BEYOND SATURDAY. FRIDAY INTO SATURDAY...WESTERLY LOW-MID LEVEL FLOW GRADUALLY BACKS IN RESPONSE TO AN APPROACHING MID LEVEL SHORT WAVE FROM THE WEST (REMNANTS OF HERMINE) AND A VORTICITY AXIS SWINGING AROUND THE BASE OF UPPER LOW OVER THE GULF OF MAINE AND NOVA SCOTIA. DEEP WEST FLOW AHEAD OF THESE FEATURES SHOULD INITIALLY LIMIT MOISTURE INFLUX. PLUS FLOW FAIRLY DIVERGENT ACROSS THE REGION LATE FRIDAY INTO EARLY SATURDAY. REMOVED SLIGHT CHANCE POP FOR LATE FRIDAY INTO FRIDAY EVENING BASED ON THIS SCENARIO. MAINTAINED A SLIGHT CHANCE POP ACROSS THE REGION SATURDAY AS MOISTURE SLOWLY INCREASES. GFS WETTER AND SLIGHTLY FASTER THAN ECMWF. IF THIS TIMING IS CORRECT...THEN COULD SEE SCATTERED SHOWERS ACROSS CENTRAL NORTH CAROLINA SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. ECMWF ABOUT 12 HOURS SLOWER WITH ITS MID LEVEL TROUGH AND DEEPEST MOISTURE ACROSS THE FORECAST AREA SATURDAY NIGHT INTO SUNDAY. FOR NOW WILL LEAN TOWARD THE SLOWER ECMWF SOLUTION. INCREASE IN CLOUDINESS SATURDAY INTO SUNDAY (ESPECIALLY SUNDAY) WILL RESULT IN A SHADING OF MAXIMUM TEMPERATURES FROM EARLIER FORECAST WHILE RAISING MINIMUM TEMPERATURES UP A COUPLE OF DEGREES. WILL PLACE THE HIGHEST POPS FOR THIS FORECAST PERIOD ON SUNDAY AND SUNDAY EVENING TO COINCIDE WITH PASSAGE OF LOW AND MID LEVEL TROUGH AND DEEPEST MOISTURE. MONDAY INTO TUESDAY WILL FEATURE AN IMPROVING WEATHER PATTERN. LOW AND MID LEVEL TROUGH SHOULD EXIT THE REGION BY EARLY MONDAY. SURFACE HIGH TO THE NORTH TO NORTHWEST WILL RESULT IN AN EAST FLOW. THIS FETCH OFF THE ATLANTIC MAY MAINTAIN LOW LEVEL MOISTURE RESULTING IN A SCATTERED AND POSSIBLY BROKEN STRATOCUMULUS FIELD. SURFACE RIDGE BECOMES MORE FIRMLY ENTRENCHED OVER THE REGION TUESDAY RESULTING IN FEWER CLOUDS. TEMPERATURES THROUGH PERIOD NEAR TO SLIGHTLY WARMER THAN NORMAL. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... AS OF 800 PM TUESDAY... AREAS OF IFR/MVFR CEILINGS WILL BE POSSIBLE BETWEEN 08 AND 13Z WEDNESDAY IN ASSOCIATION WITH WARM ADVECTION AHEAD OF AN APPROACHING FRONT...WITH KFAY THE MOST LIKELY (RELATIVELY SPEAKING) TAF SITE TO SEE LOW CEILINGS. AFTER SUNRISE WEDNESDAY...A COLD FRONT WILL APPROACH FROM THE NORTHWEST. ANY LOW CLOUDS SHOULD MIX OUT QUICKLY WITH INCREASING SW/WESTERLY SURFACE FLOW AHEAD OF THE COLD FRONT. A PREFRONTAL TROUGH WILL DROP SOUTHEAST THROUGH CENTRAL NORTH CAROLINA IN EARLY TO MID AFTERNOON...SWITCHING SURFACE WINDS AROUND FROM SOUTHWEST TO WEST SOUTHWEST ... TO WEST...WHILE THE FRONT ITSELF HOLDS OFF TO OUR NORTHWEST UNTIL WEDNESDAY NIGHT. A FEW SPRINKLES OR SHOWERS ARE EXPECTED JUST AHEAD OF THE FRONT LOOKING BEYOND WEDNESDAY EVENING...VFR CONDITIONS WILL RULE INTO FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. MVFR CEILINGS ARE POSSIBLE LATE FRIDAY NIGHT INTO SATURDAY AS THE FRONT TO OUR SOUTH TRIES TO HEAD BACK NORTH AS A WARM FRONT. A FEW SHOWERS OR STORMS ARE POSSIBLE SATURDAY INTO SUNDAY AS WE GET INTO THE WARM SECTOR AND DESTABILIZE. -VINCENT/GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS... NEAR TERM... SHORT TERM...WSS LONG TERM...WSS AVIATION... 000 FXUS62 KMHX 080051 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 851 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL EXTEND SOUTHWEST INTO THE AREA THROUGH TONIGHT. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. WEAK HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY. A WARM FRONT WILL LIFT NORTH THROUGH THE REGION ON SATURDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST SUNDAY AND MOVE INTO THE AREA MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 845 PM TUESDAY...HIGH PRES WILL CONT TO EXTEND SW INTO THE REGION TONIGHT. LOOKS LIKE BEST GRDNT WILL BE INLAND AND N AND MAY SEE LOW TEMPS THESE REGION A BIT HIGHER THEN SRN CST WHERE WINDS WILL LIKELY GO CALM. LOWERED TEMPS A BIT OBX AND SRN CST OTHERWISE NO CHANGE WITH CLR SKIES INIT THEN POSS SOME THIN HIGH CLDS LATE. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 245 PM TUESDAY...THE UPPER RIDGE WILL RETROGRADE TO THE SW WITH TROUGHING DEVELOPING OVER THE EASTERN US. THIS WILL ALLOW A WEAK COLD FRONT WITH LIMITED MOISTURE TO APPROACH THE AREA LATE WEDNESDAY AND CROSS THE REGION WEDNESDAY NIGHT. AHEAD OF THE FRONT SW FLOW WILL PRODUCE VERY WARM READINGS WITH HIGHS IN THE LOWER 90S EXPECTED...A LITTLE COOLER ALONG THE COAST SOUTH OF OREGON INLET WHERE THE SEA BREEZE WILL OCCUR. PREVIOUS SHIFT ADDED A SLIGHT CHANCE FOR RAIN AHEAD OF THE FRONT INLAND/CHANCE IMMEDIATE COAST FOR A SHOWER/THUNDERSTORM FROM 22Z-09Z WEDNESDAY/WEDNESDAY NIGHT AND WILL STAY WITH THIS THINKING WITH NEGATIVE LI`S AND DECENT LOW LEVEL CONVERGENCE FORECAST OVER EASTERN NC WEDNESDAY NIGHT. THE GFS WAS THE WETTEST OF THE 12Z MODELS WITH THIS FEATURE SO BLENDED THIS WITH THE DRIER ECMWF AND MIDDLE OF THE ROAD NAM. TEMPERATURES WILL COOL INTO THE MIDDLE 60S BEHIND THE FRONT WEDNESDAY NIGHT AND MIDDLE TO A FEW UPPER 80S THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 245 PM TUESDAY...ANTICIPATE SUBSIDENCE BEHIND THE COLD FRONT TO CONTINUE INTO FRIDAY WITH DRY CONDITIONS. UPPER LEVEL TROUGHING WILL SLOWLY MIGRATE OFF THE NEW ENGLAND COAST EARLY SATURDAY GIVING WAY TO MID/UPPER LEVEL RIDGING. THE REMNANTS OF TS HERMINE WILL BE INFLUENCED BY THE WESTERLIES AS IT TRAVELS NORTH INTO THE CENTRAL CONUS THURSDAY INTO FRIDAY. GFS/ECMWF BOTH HAVE THE VORT MAX ASSOCIATED WITH THIS SYSTEM CROSSING EASTERN NC EARLY SATURDAY AS IT GETS CAUGHT IN THE UPPER LEVEL TROUGH SET TO THE NORTH. HOWEVER...THE REMNANTS MAY GET INFUSED WITH A COLD FRONT MOVING ACROSS THE LEE SIDE OF THE ROCKIES FRIDAY. WILL NEED TO MONITOR THE TIMING ON THIS. REGARDLESS...IT SEEMS THE BULK OF THE MOISTURE WILL ACCOMPANY THE COLD FRONT AS IT APPROACHES THE AREA LATER IN THE WEEKEND. A WARM FRONT WILL INCREASE THE CHANCE OF PRECIPITATION SATURDAY...WHILE THE BEST CONVERGENCE/LIFT/MOISTURE WILL BE SUNDAY INTO EARLY MONDAY IN ASSOCIATION WITH THE FRONTAL BOUNDARY. LI VALUES SUGGEST THE POSSIBILITY FOR SOME CONVECTION SUNDAY INTO SUNDAY NIGHT. THEREFORE...HAVE MODIFIED THE FORECAST SLIGHTLY TO REFLECT THIS TREND. TEMPERATURES WILL BE NEAR SEASONABLE NORMALS WITH COOLEST READINGS OCCURRING THURSDAY NIGHT WHEN RADIATIONAL COOLING LEADS TO LOWS IN THE UPPER 50S INLAND. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 815 PM TUE...CLEAR SKIES WILL BE DOMINATING UNTIL A BROKEN LAYER OF CIRRUS WILL BE PASSING OVERHEAD AFTER MIDNIGHT WHICH WILL HELP LIMIT FOG FORMATION. OVERNIGHT...WINDS WILL BE CALM TO LIGHT/VARIABLE. CLOUD COVER AND SW WINDS WILL INCREASE WEDNESDAY AFTERNOON AHEAD OF THE WEAK FRONTAL BOUNDARY FROM THE NW. BEST CHANCE OF PRECIPITATION WILL BE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING. THE FRONT WILL MOVE OFF THE COAST BY EARLY MORNING THURSDAY. WINDS WILL BECOME NORTHERLY 5-10 KNOTS BEHIND THE FRONT FOR THURSDAY. A VERY DRY AIRMASS WILL MOVE IN BEHIND THE FRONT WITH ONLY A BROKEN LAYER OF JET STREAM CIRRUS EXPECTED. THE FL0W WILL BE LIGHT THROUGH THE REMAINDER OF THE PERIOD. AN UNSETTLED PERIOD IN STORE THIS WEEKEND. THE FRONT WILL LIFT BACK NORTH THROUGH THE AREA AS A WARM FRONT AS THE FLOW BECOMES SOUTHERLY AHEAD OF ANOTHER COLD FRONT WHICH WILL APPROACH FROM THE WEST ON SUNDAY. THE FRONT IS EXPECTED TO MOVE OFF THE COAST MONDAY MORNING. CONVECTION POSSIBLE THROUGH THE WEEKEND BUT IS EXPECTED TO BE SCATTERED. && && .MARINE... AS OF 845 PM TUE...OBS FROM LAND/BUOY SITES SHOW MARINE PACKAGE IN GOOD SHAPE. NO CHANGES MADE THIS EVENING. PREV DISC...AGAIN TODAY THE 12Z GFS/NAM ARE IN GOOD AGREEMENT THROUGH THE PERIOD. AXIS OF HIGH PRESSURE OVER THE REGION WILL MOVE OFF THE COAST TONIGHT. THE FLOW WILL BECOME SOUTHWEST AS COLD FRONT APPROACHES FROM THE NORTHWEST. SPEEDS WILL GENERALLY BE 5-10 KNOTS EXCEPT OVER THE NORTHERN WATERS WHERE 10-15 KNOTS EXPECTED IN TIGHTER PRESSURE GRADIENT. THE FRONT WILL MOVE THROUGH THE MARINE ZONES LATE WEDNESDAY NIGHT AND BE OFF THE COAST EARLY THURSDAY WHERE IT WILL BECOME STATIONARY THURSDAY INTO FRIDAY. SMALL CRAFT CONDITIONS NOT EXPECTED AS THE PRESSURE GRADIENT WILL REMAIN RATHER LOOSE. POST-FRONTAL WINDS ON THURSDAY WILL BE FROM THE NORTH AT 10-15 KNOTS DIMINISHING TO 5-10 KNOTS IN THE AFTERNOON. LIGHT WINDS AND SEAS IN STORE FOR THURSDAY NIGHT INTO SUNDAY. THE FRONT WILL LIFT BACK NORTH THROUGH THE AREA AS A WARM FRONT THIS WEEKEND AS THE FLOW BECOMES SOUTHERLY AHEAD OF ANOTHER COLD FRONT WHICH WILL APPROACH FROM THE WEST ON SUNDAY. THE FRONT IS EXPECTED TO MOVE OFF THE COAST MONDAY MORNING. SCATTERED CONVECTION POSSIBLE THIS WEEKEND. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...RF SHORT TERM...JME LONG TERM...LP/JME AVIATION...BM/HSA MARINE...HSA 000 FXUS62 KRAH 072357 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 757 PM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TONIGHT. A WEAK COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA LATE WEDNESDAY THROUGH WEDNESDAY NIGHT. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THURSDAY INTO FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... AS OF 230 PM TUESDAY... THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED OFF THE NRN COAST OF NC AND RIDGING BACK TOWARD THE SW THROUGH CENTRAL NC. THE SCATTERED AFTERNOON CUMULUS CLOUDS... WHOSE VERTICAL EXTENT HAS BEEN HINDERED BY THE CAPPING INVERSION ALOFT... WILL SLOWLY DISSIPATE BY EARLY EVENING WITH THE LOSS OF HEATING. THE COLD FRONT... LOCATED FROM ERN MI THROUGH SRN IL TO OK THIS AFTERNOON... APPROACHES OUR AREA LATE TONIGHT AS THE RIDGE AXIS SINKS SLOWLY TO THE SE. EXPECT MID AND HIGH CLOUDS... NOW OVER WRN KY/WRN TN AND AR... TO SPREAD AHEAD OF THE FRONT RESULTING IN STEADILY INCREASING/THICKENING SKY COVER ACROSS THE NW CWA LATE TONIGHT. IN THE SOUTHEAST CWA... LIGHTER WINDS ALONG WITH MODEL PROJECTIONS OF RESIDUAL NEAR-SURFACE MOISTURE... HIGH DEW POINTS... AND A LACK OF HIGH CLOUDS NECESSITATES BRINGING IN A MENTION OF PATCHY FOG AND LOW STRATUS IN THE SE CWA OVERNIGHT. BUT AS IS OFTEN THE CASE WITH SUCH LOW LEVEL FLOW PATTERNS... THE OCCURRENCE OF FOG/STRATUS IN THE ERN CWA IS UNCERTAIN. LOWS 65-69... NOTABLY WARMER THAN LAST NIGHT GIVEN THE HIGHER DEW POINTS AND STIRRED LOW LEVELS. FOR WEDNESDAY/WEDNESDAY NIGHT: THE SOUTHWESTERLY BREEZE WILL RAMP UP BY MID MORNING AS THE MSLP GRADIENT TIGHTENS AHEAD OF THE FRONT. A PREFRONTAL TROUGH DROPS SE THROUGH THE AREA FROM LATE MORNING THROUGH MID AFTERNOON... SHIFTING THE SW WINDS AROUND TO W AND WNW... WHILE THE FRONT ITSELF APPEARS TO BE HELD UP BY THE HIGHER TERRAIN... UNLIKELY TO PUSH THROUGH UNTIL AFTER SUNSET. LOW LEVEL THICKNESSES ARE WELL ABOVE NORMAL... CLIMBING UP ABOVE 1420 M WEDNESDAY AFTERNOON... AND WITH A DOWNSLOPE WIND COMPONENT FACILITATING A DRY ADIABATIC LOW LEVEL PROFILE... EXPECT HIGHS ABOUT 2 CATEGORIES ABOVE NORMAL... 90-95. WHILE FORECAST SOUNDINGS SHOW THE MID AND UPPER LEVELS MOISTENING UP... REASONABLE CONSIDERING THE UPSTREAM CONDITIONS CURRENTLY... THE WESTERLY LOW LEVEL FLOW WILL KEEP THE SUBCLOUD LAYER SUFFICIENTLY DRY AND DEEP TO LIMIT PRECIP CHANCES. BUT CONSIDERING THE UPSTREAM MOISTURE (PW OF 1.8-2.2" NOSING INTO WRN TN ACCORDING TO BLENDED TPW IMAGERY)... PROJECTIONS OF OUR LOCAL PW RISING OVER 1.8"... AND DECENT (ALBEIT SHALLOW) FORCING FOR ASCENT GENERATED BY MID LEVEL DPVA AS A VORTICITY LOBE DROPS THROUGH... WILL LEAVE IN A CHANCE OF SPRINKLES. IF THIS MODEL TREND TOWARD A SHALLOWER DRY SUBCLOUD LAYER AND/OR BETTER LIFT PERSISTS... ENSUING SHIFTS MAY NEED TO RAISE POPS TO ISOLATED OR SCATTERED SHOWERS. EXPECT THIS RISK OF A LIGHT SHOWER OR SPRINKLE TO PUSH SE THROUGH THE AREA THROUGH THE EVENING... ACCOMPANIED BY PARTLY TO MOSTLY CLOUDY SKIES... AND FOLLOWED BY CLEARING SKIES OVERNIGHT AS THE COLD FRONT DROPS THROUGH AND WEAK COOL AIR ADVECTION BEGINS WITH HIGH PRESSURE BUILDING IN FROM THE NNW. LOWS 60 NORTH TO 68 SOUTH. -GIH && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 245 PM TUESDAY... THURSDAY INTO THURSDAY NIGHT...IN WAKE OF EXITING SURFACE FRONT WINDS WILL VEER TO THE NW AND ADVECT SLIGHTLY COOLER DRIER AIR INTO CENTRAL NC. LOW LEVEL THICKNESSES FAIRLY CLOSE TO NORMAL FOR EARLY SEPTEMBER AND MOS GUIDANCE CORRESPOND FAIRLY WELL TO THESE LEVELS. THUS HAVE LOWERED MAX TEMPS ABOUT 3 DEGREES FROM PREVIOUS FORECAST. (MAX TEMPS 85 FAR NORTH TO 89 SW).CAVEAT TO FORECAST WILL BE THE POTENTIAL FOR OROGRAPHIC HIGH CLOUDS TO OCCUR...ESPECIALLY OVER THE SW HALF OF THE FORECAST AREA. PARAMETERS APPEAR TO BE IN PLACE WITH A STABLE AIR MASS ALOFT...AN UPPER LEVEL MOISTURE SOURCE OVER THE OH VALLEY AND MID-UPPER LEVEL WINDS OF SUFFICIENT STRENGTH/ORIENTATION. GFS RH CROSS SECTIONS APPEAR TO PICK UP ON THIS SCENARIO. IF CIRRUS SHIELD THICK ENOUGH...THEN MAX TEMPS ACROSS THE SW COUNTIES MAY END UP BEING A COUPLE OF DEGREES COOLER THAN FORECAST. MAY SEE SOME THINNING OF CIRRUS SHIELD THU NIGHT. HOWEVER ENOUGH MOISTURE MAY REMAIN TO KEEP SOME CLOUDS OVER THE SOUTHERN COUNTIES. THIS SHOULD LEAD TO MIN TEMPS BEING A COUPLE OF DEGREES WARMER THAN PREVIOUSLY FORECAST. EXPECT MAINLY CLEAR SKIES AND A LIGHT/CALM WIND REGIME ACROSS THE NE UNDERNEATH THE SURFACE RIDGE. THIS SHOULD SUPPORT COOLER MIN TEMPS. MIN TEMPS MID 50S FAR NE TO MID 60S S-SW. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 246 PM TUESDAY... UPPER AIR PATTERN THROUGH THE PERIOD WILL BE CHARACTERIZED BY A BROAD UPPER LEVEL RIDGE STRETCHING WEST-TO-EAST ACROSS TEXAS AND THE GULF WHILE THE MAIN BAND OF WESTERLIES WILL EXTEND FROM THE PACIFIC NORTHWEST THROUGH THE NORTHERN PLAINS AND GREAT LAKES TO SOUTHERN NEW ENGLAND. THIS TYPE OF PATTERN FOR CENTRAL NC USUALLY SPELLS DRY WEATHER WITH SLIGHTLY ABOVE NORMAL TEMPS. MODEL GUIDANCE IN GENERALLY GOOD AGREEMENT WITH SOME TIMING ISSUES BEYOND SATURDAY. FRIDAY INTO SATURDAY...WESTERLY LOW-MID LEVEL FLOW GRADUALLY BACKS IN RESPONSE TO AN APPROACHING MID LEVEL S/W FROM THE WEST (REMNANTS OF HERMINE) AND A VORTICITY AXIS SWINGING AROUND THE BASE OF UPPER LOW OVER THE GULF OF MAINE/NOVA SCOTIA. DEEP WLY FLOW AHEAD OF THESE FEATURES SHOULD INITIALLY LIMIT MOISTURE INFLUX. PLUS FLOW FAIRLY DIVERGENT ACROSS THE REGION LATE FRIDAY INTO EARLY SATURDAY. REMOVED SLIGHT CHANCE POP FOR LATE FRIDAY INTO FRIDAY EVENING BASED ON THIS SCENARIO. MAINTAINED A SLIGHT CHANCE POP ACROSS THE REGION SATURDAY AS MOISTURE SLOWLY INCREASES. GFS WETTER AND SLIGHTLY FASTER THAN ECMWF. IF THIS TIMING IS CORRECT...THEN COULD SEE SCATTERED SHOWERS ACROSS CENTRAL NC SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. ECMWF ABOUT 12 HOURS SLOWER WITH ITS MID LEVEL TROUGH AND DEEPEST MOISTURE ACROSS THE FORECAST AREA SATURDAY NIGHT INTO SUNDAY. FOR NOW WILL LEAN TOWARD THE SLOWER ECMWF SOLUTION. INCREASE IN CLOUDINESS SATURDAY INTO SUNDAY (ESPECIALLY SUNDAY) WILL RESULT IN A SHADING OF MAX TEMPS FROM EARLIER FORECAST WHILE RAISING MIN TEMPS UP A COUPLE OF DEGREES. WILL PLACE THE HIGHEST POPS FOR THIS FORECAST PERIOD ON SUNDAY/SUNDAY EVENING TO COINCIDE WITH PASSAGE OF LOW-MID LEVEL TROUGH AND DEEPEST MOISTURE. MONDAY INTO TUESDAY WILL FEATURE AN IMPROVING WEATHER PATTERN. LOW-MID LEVEL TROUGH SHOULD EXIT THE REGION BY EARLY MONDAY. SURFACE HIGH TO THE N-NW WILL RESULT IN AN ELY FLOW. THIS FETCH OFF THE ATLANTIC MAY MAINTAIN LOW LEVEL MOISTURE RESULTING IN A SCATTERED AND POSSIBLY BROKEN STRATO CU FIELD. SURFACE RIDGE BECOMES MORE FIRMLY ENTRENCHED OVER THE REGION TUESDAY RESULTING IN FEWER CLOUDS. TEMPS THROUGH PERIOD NEAR TO SLIGHTLY WARMER THAN NORMAL. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 800 PM TUESDAY... AREAS OF IFR/MVFR CEILINGS WILL BE POSSIBLE BETWEEN 08-13Z WED IN ASSOC/W WARM ADVECTION AHEAD OF AN APPROACHING FRONT...WITH KFAY THE MOST LIKELY (RELATIVELY SPEAKING) TAF SITE TO SEE LOW CEILINGS. AFTER SUNRISE WEDNESDAY...A COLD FRONT WILL APPROACH FROM THE NW. ANY LOW CLOUDS SHOULD MIX OUT QUICKLY WITH INCREASING SW/WESTERLY SURFACE FLOW AHEAD OF THE COLD FRONT. A PREFRONTAL TROUGH WILL DROP SE THROUGH CENTRAL NC IN EARLY-MID AFTERNOON...SWITCHING SURFACE WINDS AROUND FROM SW/WSW TO WEST...WHILE THE FRONT ITSELF HOLDS OFF TO OUR NW UNTIL WEDNESDAY NIGHT. A FEW SPRINKLES OR SHOWERS ARE EXPECTED JUST AHEAD OF THE FRONT LOOKING BEYOND WEDNESDAY EVENING...VFR CONDITIONS WILL RULE INTO FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. MVFR CIGS ARE POSSIBLE LATE FRIDAY NIGHT INTO SATURDAY AS THE FRONT TO OUR SOUTH TRIES TO HEAD BACK NORTH AS A WARM FRONT. A FEW SHOWERS OR STORMS ARE POSSIBLE SATURDAY INTO SUNDAY AS WE GET INTO THE WARM SECTOR AND DESTABILIZE. -VINCENT/GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...WSS LONG TERM...WSS AVIATION...VINCENT/HARTFIELD 000 FXUS62 KILM 072324 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 723 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH WEDNESDAY. THE ARRIVAL OF A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN THROUGH THURSDAY. A TRANSITION TO A LATE SUMMER AIR-MASS THIS WEEKEND WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY. WEAK HIGH PRESSURE WILL FOLLOW MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 3 PM TUESDAY...SFC HIGH PRESSURE SETTLING OVER THE SOUTHEAST WITH RIDGE BUILDING ALOFT. PLENTY OF SUBSIDENCE AND DRY AIR IN PLACE THROUGH MID LEVELS...WILL KEEP A NICE LID ON ANY SHOWERS THROUGH THE REMAINDER OF THE DAY. CU WILL REMAIN INLAND AND CONCENTRATED ALONG SEA BREEZE BOUNDARY BUT WILL DISSIPATE AS SOON AS HEATING OF DAY CUTS OFF...LEAVING MOSTLY CLEAR SKIES OVERNIGHT. WINDS WILL ALSO DIE DOWN THIS EVENING...BECOMING CALM MOST PLACES AS HIGH PRESSURE HOLDS ON OVERHEAD AND ATMOSPHERE DECOUPLES. PCP WATER REMAINS DOWN AROUND AN INCH THROUGH TONIGHT AND ALTHOUGH ON SHORE FLOW BECOMES MORE SOUTHERLY BY MORNING...THE INCREASE IN DEEPER LAYER MOISTURE WILL NOT COME UNTIL LATER ON WED. CLEAR SKIES AND CALM WINDS WILL HELP TO PRODUCE SOME DECENT RADIATIONAL COOLING TONIGHT. MOIST ONSHORE COMPONENT TO FLOW WILL COMBINE WITH CLEAR SKIES AND LIGHT WINDS TO PRODUCE AREAS OF FOG AFTER MIDNIGHT TONIGHT. TEMPS OVERNIGHT WILL DROP TO MID 60S INLAND TO AROUND 70 AT THE COAST. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS MIDDLE AMERICA...A TROUGH WILL HAVE A TENDENCY TO DIG ALONG THE ATLANTIC COAST. THIS MAY WELL BE SUFFICIENT ENOUGH TO ALLOW A COLD FRONT TO REACH THE CAROLINAS WED NIGHT. SOME OF THE MOISTURE FROM FORMER TROPICAL STORM HERMINE MAY BEGIN TO GET ENTRAINED WITHIN THIS FRONTAL ZONE AS IT MOVES FURTHER S WED NIGHT AND THU. STILL LOOKS LIKE ONLY A SMALL CHANCE FOR MEASURABLE RAIN. THE SMALL CHANCES FOR CONVECTION SHOULD CONTINUE INTO THU...PRIMARILY ALONG THE COAST...AS THE COLD FRONT HANGS UP AND LOW LEVEL CONVERGENCE DEVELOPS ALONG THE SEABREEZE BOUNDARY. AT THIS TIME...NO SIGNIFICANT RAIN IS EXPECTED AS THERE IS JUST SO MUCH DRY AIR TO OVERCOME. OUR STRING OF DRY DAYS STANDS AT ABOUT 2 WEEKS AND COUNTING FOR ALMOST ALL OF US. A DRY AND SLIGHTLY COOLER AIRMASS SHOULD GET REINFORCED LATE THU NIGHT. MAXIMUMS ON WED WILL BE HIGHER THAN ON THU...BUT BOTH DAYS WILL BE ABOVE NORMAL...EXCEPT ALONG THE COAST ON THU WHEN TEMPS WILL BE ABOUT NORMAL. DID NOT GO AS HIGH AS SOME OF THE MODEL OUTPUT FOR WED AS DO EXPECT CLOUDS TO BE ON THE INCREASE WITH THE APPROACH OF PEAK HEATING. SEABREEZE WILL MAKE BETTER INLAND PROGRESS THU THAN ON WED. A NOTICEABLE DROP IN DEWPOINTS IS EXPECTED ON THU...ESPECIALLY AWAY FROM THE COAST. DEWPOINTS MAY DROP TO THE MID AND UPPER 50S WITH A FEW SPOTS AS LOW AS THE LOWER 50S FROM KMEB TO KLBT TO KEYF TO WATHA. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...CONFIDENCE IS LOW FOR THIS EXTENDED FORECAST... ESPECIALLY REGARDING POTENTIAL UNSETTLED WX DURING THE WEEKEND. GFS AND ECMWF BOTH BRING THE REMNANT MOISTURE PLUME OF HERMINE ALL THE WAY OVER THE TOP OF THE UPPER RIDGE...AND ACROSS THE VIRGINIAS AND/OR THE CAROLINAS. GFS BRINGS THIS FEATURE THROUGH ON SATURDAY...WITH A COLD FRONT TO FOLLOW ON SUNDAY NIGHT. ECMWF IS NOTICEABLY SLOWER. BOTTOM LINE IS THAT CHANCE POPS ARE JUSTIFIED SAT THROUGH SUN NIGHT...WITH THINGS DRYING OUT EARLY NEXT WEEK. TEMPS WILL RUN ABOVE NORMAL THRU THE WEEKEND... ESPECIALLY BY NIGHT DUE TO CLOUDS AND TROPICAL MOISTURE...THEN BACK NEAR CLIMO MON-TUE. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... AS OF 00Z...MODERATE CONFIDENCE THROUGH THE VALID PERIOD DUE TO POTENTIAL FOG OVERNIGHT. DIURNAL CU WILL RAPIDLY DISSIPATE THIS EVE LEAVING SKC OVER THE TERMINALS. WITH TD/S IN THE MID 60S TO LOW 70S...AND WINDS EXPECTED TO BECOME NEAR CALM...ANOTHER CHALLENGING FOG FORECAST EXISTS FOR OVERNIGHT. THERE ARE TWO SIGNIFICANT DIFFERENCES BETWEEN LAST NIGHT AND TONIGHT WHICH PLAY INTO THE FOG POTENTIAL. THE LLJ WHICH DEVELOPED JUST ABOVE THE B/L LAST NIGHT WILL NOT FORM TONIGHT...AND THE LAYER OF MOISTURE IN THE COLUMN IS MUCH MORE SHALLOW THAN IT WAS ON MONDAY NIGHT. THE MISSING LLJ SHOULD ELIMINATE MUCH STRATUS OVERNIGHT SO MORE RADIATIONAL COOLING IS LIKELY...BUT THE SHALLOW MOISTURE LAYER WILL NOT PERMIT DENSE FOG. XOVERS WILL LIKELY NOT BE MET...AND MOISTURE ADVECTION WILL NOT BE AS PRONOUNCED AS LAST NIGHT EITHER. ALL OF THIS TOGETHER LEADS TO A FORECAST OF MVFR FOG...WITH THE BEST CHANCES BEING AT FLO/CRE. WITH A LIGHT SW WIND FORECAST TO DEVELOP...CRE MAY HAVE THE WORST VSBYS OVERNIGHT DUE TO LOCAL EFFECTS. WILL HAVE TO MONITOR CHANGING CONDITIONS AND UPDATE WITH 06Z ISSUANCE. AFTER SUNRISE FOG WILL RAPIDLY BURN OFF LEAVING ONLY A FEW CLOUDS THROUGH THE MORNING. WITH SUBSIDENCE THROUGH THE COLUMN AM NOT EXPECTING MUCH CU ON WEDNESDAY...BUT SCT VFR CU WILL LIKELY DEVELOP DURING THE AFTN. WINDS WILL BECOME SOUTHWESTERLY DURING WEDNESDAY...AND RANGE FROM LESS THAN 10 KTS INLAND...TO 8 TO 12 KTS AT THE COAST. EXTENDED OUTLOOK...MORNING FOG POSSIBLE EACH MORNING. COLD FRONT WILL APPROACH THE AREA THURSDAY MORNING WITH A SLIGHT CHANCE OF SHOWERS. MORE SHOWERS ARE POSSIBLE FOR THE WKND WITH THE ADVANCE OF A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM TUESDAY...ON SHORE FLOW COMBINED WITH SEA BREEZE WILL PRODUCE WINDS AROUND 10 TO 15 KTS WITH SOME HIGHER GUSTS IN THE NEAR SHORE WATERS CLOSER TO THE COAST THROUGH EARLY THIS EVENING. THIS WILL ALSO PRODUCE SOME CHOP AND SLIGHTLY HIGHER SEAS OVER THE NEAR SHORE WATERS. WINDS TONIGHT WILL REMAIN 10 KTS OR LESS. OVERALL SEAS WILL REMAIN 2 FT OR LESS. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...WINDS WILL BE FROM THE SW AHEAD OF A COLD FRONT WHICH IS EXPECTED TO MOVE ACROSS THE WATERS LATE WED NIGHT. WINDS WILL SHIFT TO NW LATE WED NIGHT AND N TO NE THU MORNING. THE SEABREEZE CIRCULATION WILL BE THE PRIMARY DRIVER OF WIND DIRECTION WED AFTERNOON AND WINDS WILL BECOME SE TO S. THE FRONT WILL BE REINFORCED AND WITH THAT WINDS WILL VEER ALL THE WAY AROUND TO NNW LATE THU NIGHT. STRONGEST WINDS THIS PERIOD ARE EXPECTED TO OCCUR WED AFTERNOON AND EVE AHEAD OF THE FRONT. AT THIS TIME...THE NORTHERLY SURGE BEHIND THE FRONT IS EXPECTED TO BE BRIEF AND WEAK. HIGHEST SEAS THIS PERIOD ARE EXPECTED TO OCCUR WED NIGHT. WINDS AND SEAS WILL REMAIN BELOW EXERCISE CAUTION CRITERIA THROUGH THE PERIOD. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...GENERAL EASTERLY COMPONENT WILL PREVAIL FRI-SAT WITH WEAK HIGH PRESSURE TO OUR NORTH. LOOK FOR A SEABREEZE-DRIVEN OSCILLATION FROM N-NE EACH MORNING...TO SE EACH AFTERNOON. SPEEDS GENERALLY 10 KT OR LESS. EXPECT VEERING WINDS SAT NIGHT...THEN PICKING UP OUT OF THE SW ON SUNDAY AHEAD OF AN APPROACHING COLD FRONT. WILL BE WELL SHORT OF ADVISORY THRESHOLDS AS 15 KT/4 FT APPEARS TO BE THE WORST-CASE. && .TIDES... THE OCCURRENCE OF THE NEW MOON ON WED WILL PRODUCE HIGH ASTRONOMICAL TIDES THROUGH MID WEEK. HIGH TIDES WILL BE RIGHT AROUND ACTION STAGE...BUT GIVEN THERE WILL BE NO STRONG ON SHORE WINDS WE SHOULD FALL JUST BELOW MINOR COASTAL FLOOD THRESHOLDS. HIGH TIDES ON WED ARE AROUND 8 AM AND 8 PM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...RJD LONG TERM...RAS AVIATION...JDW TIDES...RJD 000 FXUS62 KILM 071919 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 319 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH WEDNESDAY. THE ARRIVAL OF A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN THROUGH THURSDAY. A TRANSITION TO A LATE SUMMER AIR-MASS THIS WEEKEND WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY. WEAK HIGH PRESSURE WILL FOLLOW MONDAY AND TUESDAY. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS OF 3 PM TUESDAY...SFC HIGH PRESSURE SETTLING OVER THE SOUTHEAST WITH RIDGE BUILDING ALOFT. PLENTY OF SUBSIDENCE AND DRY AIR IN PLACE THROUGH MID LEVELS...WILL KEEP A NICE LID ON ANY SHOWERS THROUGH THE REMAINDER OF THE DAY. CU WILL REMAIN INLAND AND CONCENTRATED ALONG SEA BREEZE BOUNDARY BUT WILL DISSIPATE AS SOON AS HEATING OF DAY CUTS OFF...LEAVING MOSTLY CLEAR SKIES OVERNIGHT. WINDS WILL ALSO DIE DOWN THIS EVENING...BECOMING CALM MOST PLACES AS HIGH PRESSURE HOLDS ON OVERHEAD AND ATMOSPHERE DECOUPLES. PCP WATER REMAINS DOWN AROUND AN INCH THROUGH TONIGHT AND ALTHOUGH ON SHORE FLOW BECOMES MORE SOUTHERLY BY MORNING...THE INCREASE IN DEEPER LAYER MOISTURE WILL NOT COME UNTIL LATER ON WED. CLEAR SKIES AND CALM WINDS WILL HELP TO PRODUCE SOME DECENT RADIATIONAL COOLING TONIGHT. MOIST ONSHORE COMPONENT TO FLOW WILL COMBINE WITH CLEAR SKIES AND LIGHT WINDS TO PRODUCE AREAS OF FOG AFTER MIDNIGHT TONIGHT. TEMPS OVERNIGHT WILL DROP TO MID 60S INLAND TO AROUND 70 AT THE COAST. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...AS A RIDGE OF HIGH PRESSURE BUILDS ACROSS MIDDLE AMERICA...A TROUGH WILL HAVE A TENDENCY TO DIG ALONG THE ATLANTIC COAST. THIS MAY WELL BE SUFFICIENT ENOUGH TO ALLOW A COLD FRONT TO REACH THE CAROLINAS WED NIGHT. SOME OF THE MOISTURE FROM FORMER TROPICAL STORM HERMINE MAY BEGIN TO GET ENTRAINED WITHIN THIS FRONTAL ZONE AS IT MOVES FURTHER S WED NIGHT AND THU. STILL LOOKS LIKE ONLY A SMALL CHANCE FOR MEASURABLE RAIN. THE SMALL CHANCES FOR CONVECTION SHOULD CONTINUE INTO THU...PRIMARILY ALONG THE COAST...AS THE COLD FRONT HANGS UP AND LOW LEVEL CONVERGENCE DEVELOPS ALONG THE SEABREEZE BOUNDARY. AT THIS TIME...NO SIGNIFICANT RAIN IS EXPECTED AS THERE IS JUST SO MUCH DRY AIR TO OVERCOME. OUR STRING OF DRY DAYS STANDS AT ABOUT 2 WEEKS AND COUNTING FOR ALMOST ALL OF US. A DRY AND SLIGHTLY COOLER AIRMASS SHOULD GET REINFORCED LATE THU NIGHT. MAXIMUMS ON WED WILL BE HIGHER THAN ON THU...BUT BOTH DAYS WILL BE ABOVE NORMAL...EXCEPT ALONG THE COAST ON THU WHEN TEMPS WILL BE ABOUT NORMAL. DID NOT GO AS HIGH AS SOME OF THE MODEL OUTPUT FOR WED AS DO EXPECT CLOUDS TO BE ON THE INCREASE WITH THE APPROACH OF PEAK HEATING. SEABREEZE WILL MAKE BETTER INLAND PROGRESS THU THAN ON WED. A NOTICEABLE DROP IN DEWPOINTS IS EXPECTED ON THU...ESPECIALLY AWAY FROM THE COAST. DEWPOINTS MAY DROP TO THE MID AND UPPER 50S WITH A FEW SPOTS AS LOW AS THE LOWER 50S FROM KMEB TO KLBT TO KEYF TO WATHA. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...CONFIDENCE IS LOW FOR THIS EXTENDED FORECAST... ESPECIALLY REGARDING POTENTIAL UNSETTLED WX DURING THE WEEKEND. GFS AND ECMWF BOTH BRING THE REMNANT MOISTURE PLUME OF HERMINE ALL THE WAY OVER THE TOP OF THE UPPER RIDGE...AND ACROSS THE VIRGINIAS AND/OR THE CAROLINAS. GFS BRINGS THIS FEATURE THROUGH ON SATURDAY...WITH A COLD FRONT TO FOLLOW ON SUNDAY NIGHT. ECMWF IS NOTICEABLY SLOWER. BOTTOM LINE IS THAT CHANCE POPS ARE JUSTIFIED SAT THROUGH SUN NIGHT...WITH THINGS DRYING OUT EARLY NEXT WEEK. TEMPS WILL RUN ABOVE NORMAL THRU THE WEEKEND... ESPECIALLY BY NIGHT DUE TO CLOUDS AND TROPICAL MOISTURE...THEN BACK NEAR CLIMO MON-TUE. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 18Z...VFR CONDITIONS ARE EXPECTED THROUGH THIS EVENING. ONLY AVIATION CONCERN WILL BE SOME LIGHT FOG TOWARD SUNRISE. ANY FOG FORMATION WILL BE SHALLOW...WITH FAIRLY STRONG WINDS AT 2K FEET WITH THE VERTICAL CHANGE IN HUMIDITY DECREASING. SOUTHERN TERMINALS STAND THE BEST CHANCE WITH THE LIGHTEST WINDS AT THE BOUNDARY LAYER. WEDNESDAY...FOG WILL MIX OUT TO UNRESTRICTED BY 13Z WITH ONLY SCATTERED CU EXPECTED. SOUTHEAST WINDS THIS AFTERNOON WILL DIMINISH FOR DIURNAL REASONS BY SUNSET. SOUTHWEST WINDS ON WEDNESDAY AHEAD OF A WEAK COLD FRONT THAT WILL DROP INTO THE REGION WEDNESDAY NIGHT. EXTENDED OUTLOOK...LOW CONFIDENCE IFR VISIBILITIES IN MORNING FOG EACH MORNING...MAINLY FLO/LBT. THERE WILL A POTENTIAL FOR ISOLATED SHOWERS/THUNDERSTORMS WEDNESDAY EVENING INTO THURSDAY MORNING ASSOCIATED WITH A COLD FRONT...AND AGAIN ON SATURDAY ASSOCIATED WITH A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM TUESDAY...ON SHORE FLOW COMBINED WITH SEA BREEZE WILL PRODUCE WINDS AROUND 10 TO 15 KTS WITH SOME HIGHER GUSTS IN THE NEAR SHORE WATERS CLOSER TO THE COAST THROUGH EARLY THIS EVENING. THIS WILL ALSO PRODUCE SOME CHOP AND SLIGHTLY HIGHER SEAS OVER THE NEAR SHORE WATERS. WINDS TONIGHT WILL REMAIN 10 KTS OR LESS. OVERALL SEAS WILL REMAIN 2 FT OR LESS. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...WINDS WILL BE FROM THE SW AHEAD OF A COLD FRONT WHICH IS EXPECTED TO MOVE ACROSS THE WATERS LATE WED NIGHT. WINDS WILL SHIFT TO NW LATE WED NIGHT AND N TO NE THU MORNING. THE SEABREEZE CIRCULATION WILL BE THE PRIMARY DRIVER OF WIND DIRECTION WED AFTERNOON AND WINDS WILL BECOME SE TO S. THE FRONT WILL BE REINFORCED AND WITH THAT WINDS WILL VEER ALL THE WAY AROUND TO NNW LATE THU NIGHT. STRONGEST WINDS THIS PERIOD ARE EXPECTED TO OCCUR WED AFTERNOON AND EVE AHEAD OF THE FRONT. AT THIS TIME...THE NORTHERLY SURGE BEHIND THE FRONT IS EXPECTED TO BE BRIEF AND WEAK. HIGHEST SEAS THIS PERIOD ARE EXPECTED TO OCCUR WED NIGHT. WINDS AND SEAS WILL REMAIN BELOW EXERCISE CAUTION CRITERIA THROUGH THE PERIOD. LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...GENERAL EASTERLY COMPONENT WILL PREVAIL FRI-SAT WITH WEAK HIGH PRESSURE TO OUR NORTH. LOOK FOR A SEABREEZE-DRIVEN OSCILLATION FROM N-NE EACH MORNING...TO SE EACH AFTERNOON. SPEEDS GENERALLY 10 KT OR LESS. EXPECT VEERING WINDS SAT NIGHT...THEN PICKING UP OUT OF THE SW ON SUNDAY AHEAD OF AN APPROACHING COLD FRONT. WILL BE WELL SHORT OF ADVISORY THRESHOLDS AS 15 KT/4 FT APPEARS TO BE THE WORST-CASE. && .TIDES... THE OCCURRENCE OF THE NEW MOON ON WED WILL PRODUCE HIGH ASTRONOMICAL TIDES THROUGH MID WEEK. HIGH TIDES WILL BE RIGHT AROUND ACTION STAGE...BUT GIVEN THERE WILL BE NO STRONG ON SHORE WINDS WE SHOULD FALL JUST BELOW MINOR COASTAL FLOOD THRESHOLDS. HIGH TIDES ON WED ARE AROUND 8 AM AND 8 PM. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...RJD LONG TERM...RAS AVIATION...DL/RGZ TIDES...RJD 000 FXUS62 KMHX 071849 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 249 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL EXTEND SOUTHWEST INTO THE AREA THROUGH TONIGHT. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. WEAK HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY. A WARM FRONT WILL LIFT NORTH THROUGH THE REGION ON SATURDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST SUNDAY AND MOVE INTO THE AREA MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 245 PM TUESDAY...HIGH PRESSURE OFFSHORE RIDGING INTO NC WILL REMAIN THE DOMINATE WEATHER FEATURE THROUGH TONIGHT. DIURNAL CUMULUS WILL DISSIPATE WITH LOSS OF SOLAR HEATING WITH SKIES BECOMING CLEAR THIS EVENING AND WINDS LIGHT. THIS WILL RESULT IN EXCELLENT RADIATIONAL COOLING OVERNIGHT. WHILE PATCHY DENSE FOG WILL BE POSSIBLE WE ARE EXPECTING MORE OF A HEAVY DEW SO WILL LEAVE FOG OUT OF THE FORECAST FOR NOW. WITH STRONG RADIATIONAL COOLING OVERNIGHT TRENDED FORECAST LOWS TOWARD THE COOLER MOS VALUES WITH READINGS RANGING FROM THE MID 60S INLAND TO THE LOWER/MIDDLE 70S BEACHES. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 245 PM TUESDAY...THE UPPER RIDGE WILL RETROGRADE TO THE SW WITH TROUGHING DEVELOPING OVER THE EASTERN US. THIS WILL ALLOW A WEAK COLD FRONT WITH LIMITED MOISTURE TO APPROACH THE AREA LATE WEDNESDAY AND CROSS THE REGION WEDNESDAY NIGHT. AHEAD OF THE FRONT SW FLOW WILL PRODUCE VERY WARM READINGS WITH HIGHS IN THE LOWER 90S EXPECTED...A LITTLE COOLER ALONG THE COAST SOUTH OF OREGON INLET WHERE THE SEA BREEZE WILL OCCUR. PREVIOUS SHIFT ADDED A SLIGHT CHANCE FOR RAIN AHEAD OF THE FRONT INLAND/CHANCE IMMEDIATE COAST FOR A SHOWER/THUNDERSTORM FROM 22Z-09Z WEDNESDAY/WEDNESDAY NIGHT AND WILL STAY WITH THIS THINKING WITH NEGATIVE LI`S AND DECENT LOW LEVEL CONVERGENCE FORECAST OVER EASTERN NC WEDNESDAY NIGHT. THE GFS WAS THE WETTEST OF THE 12Z MODELS WITH THIS FEATURE SO BLENDED THIS WITH THE DRIER ECMWF AND MIDDLE OF THE ROAD NAM. TEMPERATURES WILL COOL INTO THE MIDDLE 60S BEHIND THE FRONT WEDNESDAY NIGHT AND MIDDLE TO A FEW UPPER 80S THURSDAY. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 245 PM TUESDAY...ANTICIPATE SUBSIDENCE BEHIND THE COLD FRONT TO CONTINUE INTO FRIDAY WITH DRY CONDITIONS. UPPER LEVEL TROUGHING WILL SLOWLY MIGRATE OFF THE NEW ENGLAND COAST EARLY SATURDAY GIVING WAY TO MID/UPPER LEVEL RIDGING. THE REMNANTS OF TS HERMINE WILL BE INFLUENCED BY THE WESTERLIES AS IT TRAVELS NORTH INTO THE CENTRAL CONUS THURSDAY INTO FRIDAY. GFS/ECMWF BOTH HAVE THE VORT MAX ASSOCIATED WITH THIS SYSTEM CROSSING EASTERN NC EARLY SATURDAY AS IT GETS CAUGHT IN THE UPPER LEVEL TROUGH SET TO THE NORTH. HOWEVER...THE REMNANTS MAY GET INFUSED WITH A COLD FRONT MOVING ACROSS THE LEE SIDE OF THE ROCKIES FRIDAY. WILL NEED TO MONITOR THE TIMING ON THIS. REGARDLESS...IT SEEMS THE BULK OF THE MOISTURE WILL ACCOMPANY THE COLD FRONT AS IT APPROACHES THE AREA LATER IN THE WEEKEND. A WARM FRONT WILL INCREASE THE CHANCE OF PRECIPITATION SATURDAY...WHILE THE BEST CONVERGENCE/LIFT/MOISTURE WILL BE SUNDAY INTO EARLY MONDAY IN ASSOCIATION WITH THE FRONTAL BOUNDARY. LI VALUES SUGGEST THE POSSIBILITY FOR SOME CONVECTION SUNDAY INTO SUNDAY NIGHT. THEREFORE...HAVE MODIFIED THE FORECAST SLIGHTLY TO REFLECT THIS TREND. TEMPERATURES WILL BE NEAR SEASONABLE NORMALS WITH COOLEST READINGS OCCURRING THURSDAY NIGHT WHEN RADIATIONAL COOLING LEADS TO LOWS IN THE UPPER 50S INLAND. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... AS OF 245 PM TUE...EXCELLENT FLYING WEATHER WILL CONTINUE THROUGH THE PERIOD. A BROKEN LAYER OF CIRRUS FORECAST BY TIME SECTIONS AND FORECAST SOUNDINGS TO PASS OVERHEAD TONIGHT WHICH WILL HELP LIMIT FOG FORMATION. WINDS OVERNIGHT WILL BE CALM TO LIGHT/VARIABLE. A SOUTHWEST FLOW FORECAST FOR WEDNESDAY AHEAD OF A COLD FRONT APPROACHING FROM THE NORTHWEST. WINDS WILL PICK UP TO 10-15 KNOTS WEDNESDAY AFTERNOON WITH ONLY SCATTERED HIGH-BASED CU. ONLY ISOLATED CONVECTION POSSIBLE ALONG/AHEAD OF THE FRONT FROM WEDNESDAY EVENING THROUGH THE PREDAWN HOURS THURSDAY. THE FRONT WILL MOVE OFF THE COAST BY EARLY MORNING THURSDAY. WINDS WILL BECOME NORTHERLY 5-10 KNOTS BEHIND THE FRONT FOR THURSDAY. A VERY DRY AIRMASS WILL MOVE IN BEHIND THE FRONT WITH ONLY A BROKEN LAYER OF JET STREAM CIRRUS EXPECTED. THE FL0W WILL BE LIGHT THROUGH THE REMAINDER OF THE PERIOD. AN UNSETTLED PERIOD IN STORE THIS WEEKEND. THE FRONT WILL LIFT BACK NORTH THROUGH THE AREA AS A WARM FRONT AS THE FLOW BECOMES SOUTHERLY AHEAD OF ANOTHER COLD FRONT WHICH WILL APPROACH FROM THE WEST ON SUNDAY. THE FRONT IS EXPECTED TO MOVE OFF THE COAST MONDAY MORNING. CONVECTION POSSIBLE THROUGH THE WEEKEND BUT IS EXPECTED TO BE SCATTERED. && .MARINE... AS OF 245 PM TUE...AGAIN TODAY THE 12Z GFS/NAM ARE IN GOOD AGREEMENT THROUGH THE PERIOD. AXIS OF HIGH PRESSURE OVER THE REGION WILL MOVE OFF THE COAST TONIGHT. THE FLOW WILL BECOME SOUTHWEST AS COLD FRONT APPROACHES FROM THE NORTHWEST. SPEEDS WILL GENERALLY BE 5-10 KNOTS EXCEPT OVER THE NORTHERN WATERS WHERE 10-15 KNOTS EXPECTED IN TIGHTER PRESSURE GRADIENT. THE FRONT WILL MOVE THROUGH THE MARINE ZONES LATE WEDNESDAY NIGHT AND BE OFF THE COAST EARLY THURSDAY WHERE IT WILL BECOME STATIONARY THURSDAY INTO FRIDAY. SMALL CRAFT CONDITIONS NOT EXPECTED AS THE PRESSURE GRADIENT WILL REMAIN RATHER LOOSE. POST-FRONTAL WINDS ON THURSDAY WILL BE FROM THE NORTH AT 10-15 KNOTS DIMINISHING TO 5-10 KNOTS IN THE AFTERNOON. LIGHT WINDS AND SEAS IN STORE FOR THURSDAY NIGHT INTO SUNDAY. THE FRONT WILL LIFT BACK NORTH THROUGH THE AREA AS A WARM FRONT THIS WEEKEND AS THE FLOW BECOMES SOUTHERLY AHEAD OF ANOTHER COLD FRONT WHICH WILL APPROACH FROM THE WEST ON SUNDAY. THE FRONT IS EXPECTED TO MOVE OFF THE COAST MONDAY MORNING. SCATTERED CONVECTION POSSIBLE THIS WEEKEND. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...JME NEAR TERM...JME SHORT TERM...JME LONG TERM...LP/JME AVIATION...HSA MARINE...HSA 000 FXUS62 KRAH 071849 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 248 PM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TONIGHT. A WEAK COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA LATE WEDNESDAY THROUGH WEDNESDAY NIGHT. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THURSDAY INTO FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 230 PM TUESDAY... THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED OFF THE NRN COAST OF NC AND RIDGING BACK TOWARD THE SW THROUGH CENTRAL NC. THE SCATTERED AFTERNOON CUMULUS CLOUDS... WHOSE VERTICAL EXTENT HAS BEEN HINDERED BY THE CAPPING INVERSION ALOFT... WILL SLOWLY DISSIPATE BY EARLY EVENING WITH THE LOSS OF HEATING. THE COLD FRONT... LOCATED FROM ERN MI THROUGH SRN IL TO OK THIS AFTERNOON... APPROACHES OUR AREA LATE TONIGHT AS THE RIDGE AXIS SINKS SLOWLY TO THE SE. EXPECT MID AND HIGH CLOUDS... NOW OVER WRN KY/WRN TN AND AR... TO SPREAD AHEAD OF THE FRONT RESULTING IN STEADILY INCREASING/THICKENING SKY COVER ACROSS THE NW CWA LATE TONIGHT. IN THE SOUTHEAST CWA... LIGHTER WINDS ALONG WITH MODEL PROJECTIONS OF RESIDUAL NEAR-SURFACE MOISTURE... HIGH DEW POINTS... AND A LACK OF HIGH CLOUDS NECESSITATES BRINGING IN A MENTION OF PATCHY FOG AND LOW STRATUS IN THE SE CWA OVERNIGHT. BUT AS IS OFTEN THE CASE WITH SUCH LOW LEVEL FLOW PATTERNS... THE OCCURRENCE OF FOG/STRATUS IN THE ERN CWA IS UNCERTAIN. LOWS 65-69... NOTABLY WARMER THAN LAST NIGHT GIVEN THE HIGHER DEW POINTS AND STIRRED LOW LEVELS. FOR WEDNESDAY/WEDNESDAY NIGHT: THE SOUTHWESTERLY BREEZE WILL RAMP UP BY MID MORNING AS THE MSLP GRADIENT TIGHTENS AHEAD OF THE FRONT. A PREFRONTAL TROUGH DROPS SE THROUGH THE AREA FROM LATE MORNING THROUGH MID AFTERNOON... SHIFTING THE SW WINDS AROUND TO W AND WNW... WHILE THE FRONT ITSELF APPEARS TO BE HELD UP BY THE HIGHER TERRAIN... UNLIKELY TO PUSH THROUGH UNTIL AFTER SUNSET. LOW LEVEL THICKNESSES ARE WELL ABOVE NORMAL... CLIMBING UP ABOVE 1420 M WEDNESDAY AFTERNOON... AND WITH A DOWNSLOPE WIND COMPONENT FACILITATING A DRY ADIABATIC LOW LEVEL PROFILE... EXPECT HIGHS ABOUT 2 CATEGORIES ABOVE NORMAL... 90-95. WHILE FORECAST SOUNDINGS SHOW THE MID AND UPPER LEVELS MOISTENING UP... REASONABLE CONSIDERING THE UPSTREAM CONDITIONS CURRENTLY... THE WESTERLY LOW LEVEL FLOW WILL KEEP THE SUBCLOUD LAYER SUFFICIENTLY DRY AND DEEP TO LIMIT PRECIP CHANCES. BUT CONSIDERING THE UPSTREAM MOISTURE (PW OF 1.8-2.2" NOSING INTO WRN TN ACCORDING TO BLENDED TPW IMAGERY)... PROJECTIONS OF OUR LOCAL PW RISING OVER 1.8"... AND DECENT (ALBEIT SHALLOW) FORCING FOR ASCENT GENERATED BY MID LEVEL DPVA AS A VORTICITY LOBE DROPS THROUGH... WILL LEAVE IN A CHANCE OF SPRINKLES. IF THIS MODEL TREND TOWARD A SHALLOWER DRY SUBCLOUD LAYER AND/OR BETTER LIFT PERSISTS... ENSUING SHIFTS MAY NEED TO RAISE POPS TO ISOLATED OR SCATTERED SHOWERS. EXPECT THIS RISK OF A LIGHT SHOWER OR SPRINKLE TO PUSH SE THROUGH THE AREA THROUGH THE EVENING... ACCOMPANIED BY PARTLY TO MOSTLY CLOUDY SKIES... AND FOLLOWED BY CLEARING SKIES OVERNIGHT AS THE COLD FRONT DROPS THROUGH AND WEAK COOL AIR ADVECTION BEGINS WITH HIGH PRESSURE BUILDING IN FROM THE NNW. LOWS 60 NORTH TO 68 SOUTH. -GIH && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 245 PM TUESDAY... THURSDAY INTO THURSDAY NIGHT...IN WAKE OF EXITING SURFACE FRONT WINDS WILL VEER TO THE NW AND ADVECT SLIGHTLY COOLER DRIER AIR INTO CENTRAL NC. LOW LEVEL THICKNESSES FAIRLY CLOSE TO NORMAL FOR EARLY SEPTEMBER AND MOS GUIDANCE CORRESPOND FAIRLY WELL TO THESE LEVELS. THUS HAVE LOWERED MAX TEMPS ABOUT 3 DEGREES FROM PREVIOUS FORECAST. (MAX TEMPS 85 FAR NORTH TO 89 SW).CAVEAT TO FORECAST WILL BE THE POTENTIAL FOR OROGRAPHIC HIGH CLOUDS TO OCCUR...ESPECIALLY OVER THE SW HALF OF THE FORECAST AREA. PARAMETERS APPEAR TO BE IN PLACE WITH A STABLE AIR MASS ALOFT...AN UPPER LEVEL MOISTURE SOURCE OVER THE OH VALLEY AND MID-UPPER LEVEL WINDS OF SUFFICIENT STRENGTH/ORIENTATION. GFS RH CROSS SECTIONS APPEAR TO PICK UP ON THIS SCENARIO. IF CIRRUS SHIELD THICK ENOUGH...THEN MAX TEMPS ACROSS THE SW COUNTIES MAY END UP BEING A COUPLE OF DEGREES COOLER THAN FORECAST. MAY SEE SOME THINNING OF CIRRUS SHIELD THU NIGHT. HOWEVER ENOUGH MOISTURE MAY REMAIN TO KEEP SOME CLOUDS OVER THE SOUTHERN COUNTIES. THIS SHOULD LEAD TO MIN TEMPS BEING A COUPLE OF DEGREES WARMER THAN PREVIOUSLY FORECAST. EXPECT MAINLY CLEAR SKIES AND A LIGHT/CALM WIND REGIME ACROSS THE NE UNDERNEATH THE SURFACE RIDGE. THIS SHOULD SUPPORT COOLER MIN TEMPS. MIN TEMPS MID 50S FAR NE TO MID 60S S-SW. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 246 PM TUESDAY... UPPER AIR PATTERN THROUGH THE PERIOD WILL BE CHARACTERIZED BY A BROAD UPPER LEVEL RIDGE STRETCHING WEST-TO-EAST ACROSS TEXAS AND THE GULF WHILE THE MAIN BAND OF WESTERLIES WILL EXTEND FROM THE PACIFIC NORTHWEST THROUGH THE NORTHERN PLAINS AND GREAT LAKES TO SOUTHERN NEW ENGLAND. THIS TYPE OF PATTERN FOR CENTRAL NC USUALLY SPELLS DRY WEATHER WITH SLIGHTLY ABOVE NORMAL TEMPS. MODEL GUIDANCE IN GENERALLY GOOD AGREEMENT WITH SOME TIMING ISSUES BEYOND SATURDAY. FRIDAY INTO SATURDAY...WESTERLY LOW-MID LEVEL FLOW GRADUALLY BACKS IN RESPONSE TO AN APPROACHING MID LEVEL S/W FROM THE WEST (REMNANTS OF HERMINE) AND A VORTICITY AXIS SWINGING AROUND THE BASE OF UPPER LOW OVER THE GULF OF MAINE/NOVA SCOTIA. DEEP WLY FLOW AHEAD OF THESE FEATURES SHOULD INITIALLY LIMIT MOISTURE INFLUX. PLUS FLOW FAIRLY DIVERGENT ACROSS THE REGION LATE FRIDAY INTO EARLY SATURDAY. REMOVED SLIGHT CHANCE POP FOR LATE FRIDAY INTO FRIDAY EVENING BASED ON THIS SCENARIO. MAINTAINED A SLIGHT CHANCE POP ACROSS THE REGION SATURDAY AS MOISTURE SLOWLY INCREASES. GFS WETTER AND SLIGHTLY FASTER THAN ECMWF. IF THIS TIMING IS CORRECT...THEN COULD SEE SCATTERED SHOWERS ACROSS CENTRAL NC SATURDAY AFTERNOON THROUGH SATURDAY NIGHT. ECMWF ABOUT 12 HOURS SLOWER WITH ITS MID LEVEL TROUGH AND DEEPEST MOISTURE ACROSS THE FORECAST AREA SATURDAY NIGHT INTO SUNDAY. FOR NOW WILL LEAN TOWARD THE SLOWER ECMWF SOLUTION. INCREASE IN CLOUDINESS SATURDAY INTO SUNDAY (ESPECIALLY SUNDAY) WILL RESULT IN A SHADING OF MAX TEMPS FROM EARLIER FORECAST WHILE RAISING MIN TEMPS UP A COUPLE OF DEGREES. WILL PLACE THE HIGHEST POPS FOR THIS FORECAST PERIOD ON SUNDAY/SUNDAY EVENING TO COINCIDE WITH PASSAGE OF LOW-MID LEVEL TROUGH AND DEEPEST MOISTURE. MONDAY INTO TUESDAY WILL FEATURE AN IMPROVING WEATHER PATTERN. LOW-MID LEVEL TROUGH SHOULD EXIT THE REGION BY EARLY MONDAY. SURFACE HIGH TO THE N-NW WILL RESULT IN AN ELY FLOW. THIS FETCH OFF THE ATLANTIC MAY MAINTAIN LOW LEVEL MOISTURE RESULTING IN A SCATTERED AND POSSIBLY BROKEN STRATO CU FIELD. SURFACE RIDGE BECOMES MORE FIRMLY ENTRENCHED OVER THE REGION TUESDAY RESULTING IN FEWER CLOUDS. TEMPS THROUGH PERIOD NEAR TO SLIGHTLY WARMER THAN NORMAL. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 100 PM TUESDAY... THE MORNING FOG AND STRATUS WAS SLOW TO MIX OUT DUE TO THE CAPPING INVERSION ALOFT AND WEAK WINDS... RESULTING IN CLOUD BASES JUST IN THE LAST HOUR HAVING RISEN ABOVE 3 KFT. THESE CLOUDS SHOULD CONTINUE TO SLOWLY LIFT AND MIX... RESULTING IN VFR CONDITIONS AT ALL SITES LASTING THROUGH THE EVENING. A HIGH PRESSURE RIDGE HOLDS ACROSS CENTRAL NC... KEEPING WINDS VERY LIGHT AND VARIABLE FROM THE SURFACE UP THROUGH THE LOWEST FEW THOUSAND FEET AGL. FLAT MOSTLY SCATTERED CUMULUS WITH BASES OF 3500-4500 FT AGL WILL DISSIPATE BY EARLY EVENING. WITH THIS RESIDUAL MOISTURE HOLDING IN THE LOW LEVELS WITH WEAK WINDS AND HIGH RELATIVE HUMIDITY OVERNIGHT... EXPECT AREAS OF FOG AND LOW CLOUDS TO FORM AFTER 06Z... MAINLY AT FAY WITH A LESSER CHANCE AT RWI/RDU. AT GSO/INT... INCREASING MID AND UPPER LEVEL CLOUDINESS AHEAD OF A COLD FRONT APPROACHING FROM THE NW WILL LIMIT RADIATIONAL COOLING AND HENCE LIMIT FOG AND LOW CLOUD DEVELOPMENT HERE. AFTER SUNRISE WEDNESDAY... A COLD FRONT WILL APPROACH FROM THE NW. THE LOW CLOUDS SHOULD MIX OUT QUICKLY WITH INCREASING SOUTHWEST SURFACE FLOW AHEAD OF THE COLD FRONT... AS MID CLOUDS (BASES ABOVE 5 KFT AGL) STEADILY INCREASE ACROSS THE AREA. A PREFRONTAL TROUGH WILL DROP SE THROUGH CENTRAL NC IN EARLY-MID AFTERNOON... SWITCHING SURFACE WINDS AROUND FROM SW TO W... WHILE THE FRONT ITSELF HOLDS OFF TO OUR NW UNTIL WEDNESDAY NIGHT. A FEW SPRINKLES OR SHOWERS ARE EXPECTED JUST AHEAD OF THE FRONT LOOKING BEYOND MID AFTERNOON WEDNESDAY... VFR CONDITIONS WILL RULE INTO FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. MVFR CIGS ARE POSSIBLE LATE FRIDAY NIGHT INTO SATURDAY AS THE FRONT TO OUR SOUTH TRIES TO HEAD BACK NORTH AS A WARM FRONT. A FEW SHOWERS OR STORMS ARE POSSIBLE SATURDAY INTO SUNDAY AS WE GET INTO THE WARM SECTOR AND DESTABILIZE. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...WSS LONG TERM...WSS AVIATION...HARTFIELD 000 FXUS62 KRAH 071837 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 235 PM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TONIGHT. A WEAK COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA LATE WEDNESDAY THROUGH WEDNESDAY NIGHT. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THURSDAY INTO FRIDAY. && .NEAR TERM /THROUGH WEDNESDAY/... AS OF 230 PM TUESDAY... THROUGH TONIGHT: THE LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED OFF THE NRN COAST OF NC AND RIDGING BACK TOWARD THE SW THROUGH CENTRAL NC. THE SCATTERED AFTERNOON CUMULUS CLOUDS... WHOSE VERTICAL EXTENT HAS BEEN HINDERED BY THE CAPPING INVERSION ALOFT... WILL SLOWLY DISSIPATE BY EARLY EVENING WITH THE LOSS OF HEATING. THE COLD FRONT... LOCATED FROM ERN MI THROUGH SRN IL TO OK THIS AFTERNOON... APPROACHES OUR AREA LATE TONIGHT AS THE RIDGE AXIS SINKS SLOWLY TO THE SE. EXPECT MID AND HIGH CLOUDS... NOW OVER WRN KY/WRN TN AND AR... TO SPREAD AHEAD OF THE FRONT RESULTING IN STEADILY INCREASING/THICKENING SKY COVER ACROSS THE NW CWA LATE TONIGHT. IN THE SOUTHEAST CWA... LIGHTER WINDS ALONG WITH MODEL PROJECTIONS OF RESIDUAL NEAR-SURFACE MOISTURE... HIGH DEW POINTS... AND A LACK OF HIGH CLOUDS NECESSITATES BRINGING IN A MENTION OF PATCHY FOG AND LOW STRATUS IN THE SE CWA OVERNIGHT. BUT AS IS OFTEN THE CASE WITH SUCH LOW LEVEL FLOW PATTERNS... THE OCCURRENCE OF FOG/STRATUS IN THE ERN CWA IS UNCERTAIN. LOWS 65-69... NOTABLY WARMER THAN LAST NIGHT GIVEN THE HIGHER DEW POINTS AND STIRRED LOW LEVELS. FOR WEDNESDAY/WEDNESDAY NIGHT: THE SOUTHWESTERLY BREEZE WILL RAMP UP BY MID MORNING AS THE MSLP GRADIENT TIGHTENS AHEAD OF THE FRONT. A PREFRONTAL TROUGH DROPS SE THROUGH THE AREA FROM LATE MORNING THROUGH MID AFTERNOON... SHIFTING THE SW WINDS AROUND TO W AND WNW... WHILE THE FRONT ITSELF APPEARS TO BE HELD UP BY THE HIGHER TERRAIN... UNLIKELY TO PUSH THROUGH UNTIL AFTER SUNSET. LOW LEVEL THICKNESSES ARE WELL ABOVE NORMAL... CLIMBING UP ABOVE 1420 M WEDNESDAY AFTERNOON... AND WITH A DOWNSLOPE WIND COMPONENT FACILITATING A DRY ADIABATIC LOW LEVEL PROFILE... EXPECT HIGHS ABOUT 2 CATEGORIES ABOVE NORMAL... 90-95. WHILE FORECAST SOUNDINGS SHOW THE MID AND UPPER LEVELS MOISTENING UP... REASONABLE CONSIDERING THE UPSTREAM CONDITIONS CURRENTLY... THE WESTERLY LOW LEVEL FLOW WILL KEEP THE SUBCLOUD LAYER SUFFICIENTLY DRY AND DEEP TO LIMIT PRECIP CHANCES. BUT CONSIDERING THE UPSTREAM MOISTURE (PW OF 1.8-2.2" NOSING INTO WRN TN ACCORDING TO BLENDED TPW IMAGERY)... PROJECTIONS OF OUR LOCAL PW RISING OVER 1.8"... AND DECENT (ALBEIT SHALLOW) FORCING FOR ASCENT GENERATED BY MID LEVEL DPVA AS A VORTICITY LOBE DROPS THROUGH... WILL LEAVE IN A CHANCE OF SPRINKLES. IF THIS MODEL TREND TOWARD A SHALLOWER DRY SUBCLOUD LAYER AND/OR BETTER LIFT PERSISTS... ENSUING SHIFTS MAY NEED TO RAISE POPS TO ISOLATED OR SCATTERED SHOWERS. EXPECT THIS RISK OF A LIGHT SHOWER OR SPRINKLE TO PUSH SE THROUGH THE AREA THROUGH THE EVENING... ACCOMPANIED BY PARTLY TO MOSTLY CLOUDY SKIES... AND FOLLOWED BY CLEARING SKIES OVERNIGHT AS THE COLD FRONT DROPS THROUGH AND WEAK COOL AIR ADVECTION BEGINS WITH HIGH PRESSURE BUILDING IN FROM THE NNW. LOWS 60 NORTH TO 68 SOUTH. -GIH && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... AS OF 230 AM TUESDAY... THURSDAY THROUGH THURSDAY NIGHT: COULD SEE A FAIR AMOUNT OF HIGH CLOUDS ACROSS THE AREA ON THURSDAY AS UPPER JET DIVES SOUTHEAST OVER THE DELMARVA REGION...DOWN THE BACK-SIDE OF THE CLOSED LOW/UPPER TROUGH. SO UNDER MOSTLY/PARTLY SUNNY SKIES HIGHS THURSDAY WILL ONCE AGAIN RANGE IN THE UPPER 80S TO LOWER 90S. COOLER THURSDAY NIGHT...WITH LOWS IN THE UPPER 50S NORTH TO MID 60S SOUTH. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 255 AM TUESDAY... LONG-TERM GUIDANCE IS FAIRLY CONSISTENT BRINGING THE REMNANT SHORTWAVE OF HERMINE AROUND THE UPPER RIDGE AND TOWARD CENTRAL NORTH CAROLINA LATE FRIDAY AND ESPECIALLY FRIDAY NIGHT. THE PRIMARY QUESTION IS HOW TRAVEL THROUGH THE RIDGE WILL AFFECT THE INTENSITY... WITH THE LATEST GFS NOT TERRIBLY STRONG WITH THE WAVE BUT ABLE TO PROVIDE PRECIPITATION...AND THE CANADIAN APPARENTLY STRONGER BUT UNABLE TO GENERATE QPF FOR CENTRAL NORTH CAROLINA. WILL REVIEW THE 00Z ECMWF BEFORE MAKING A FINAL DECISION...BUT THE ONGOING FORECAST OF CHANCES OF SHOWERS WILL LIKELY BE KEPT INTACT AS THESE REMNANT TROPICAL WAVES OFTEN SEEM TO BE ABLE TO MAINTAIN SOME INTENSITY AND PROVIDE FOR AT LEAST SCATTERED SHOWERS AT TIMES BEFORE THEY COMPLETELY DIMINISH. IN THIS CASE...BELIEVE THE RIDGE WILL WEAKEN THE MID-LEVEL WAVE...BUT NOT ENOUGH TO LOWER CHANCES OF SHOWERS FROM THE FORECAST. GFSX MOS ENSEMBLE GUIDANCE IS ABOVE CLIMATOLOGY WITH REGARD TO CHANCES FOR SHOWERS SATURDAY THROUGH MONDAY. THE GFS PERSISTS A SURFACE WAVE IN THE FRONTAL ZONE JUST SOUTH OF THE STATE SATURDAY INTO SUNDAY...WITH THE CANADIAN SHOWING MORE SURFACE RIDGING SATURDAY BEFORE INTRODUCING MORE OF AN INVERTED TROUGH EXTENDING NORTH INTO THE STATE SUNDAY FROM LOW PRESSURE TO THE SOUTH. PRECIPITATION IS FORECAST MORE BY THE CANADIAN SUNDAY VERSUS SATURDAY...AND CURRENTLY THINK THIS IS THE MORE LIKELY SCENARIO IF THE TIMING OF THE MID-LEVEL WAVE LATE FRIDAY AND EARLY SATURDAY VERIFIES WITH SUBSIDENCE IN THE WAKE OF THE WAVE...FOLLOWED BY A QUICK RETURN OF SOME MOISTURE AND LIFT ON SUNDAY. GIVEN THE UNCERTAINTY WILL NOT REMOVE SLIGHT CHANCES FROM THE FORECAST SATURDAY...BUT OPTED TO RAISE POPS TO CHANCE FOR SUNDAY BASED ON THE CONSENSUS OF THE LONG-TERM GUIDANCE...HIGHEST ENSEMBLE MOS POPS FROM THE GFSX FOR SUNDAY...AND THE FACT THAT THIS IS THE THIRD RUN IN A ROW BY THE GFS WITH QPF ON SUNDAY. WITH MORE OF A NORTHWEST FLOW ALOFT DEVELOPING BY MONDAY...MADE THAT DAY DRY...AS BOTH THE 00Z GFS AND CANADIAN BRING A GOOD PUSH OF MEAN DRY AIR INTO THE STATE BY THEN. ONGOING FORECAST HIGH TEMPERATURES ARE MOSTLY AT OR BELOW OPERATIONAL MEX MOS...AND IN THE RANGE OF MOST OF THE GFSX MOS ENSEMBLE GUIDANCE WITH READINGS SOLIDLY IN THE 80S. AN ALTERNATIVE IS THAT ONE DAY...MOST LIKELY SUNDAY...COULD BE COOLER THAN FORECAST IF THERE IS ENOUGH CLOUDS AND PRECIPITATION... BUT CONFIDENCE IN THIS IS TOO LOW THIS FAR OUT TO MAKE ANY ADJUSTMENTS. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 100 PM TUESDAY... THE MORNING FOG AND STRATUS WAS SLOW TO MIX OUT DUE TO THE CAPPING INVERSION ALOFT AND WEAK WINDS... RESULTING IN CLOUD BASES JUST IN THE LAST HOUR HAVING RISEN ABOVE 3 KFT. THESE CLOUDS SHOULD CONTINUE TO SLOWLY LIFT AND MIX... RESULTING IN VFR CONDITIONS AT ALL SITES LASTING THROUGH THE EVENING. A HIGH PRESSURE RIDGE HOLDS ACROSS CENTRAL NC... KEEPING WINDS VERY LIGHT AND VARIABLE FROM THE SURFACE UP THROUGH THE LOWEST FEW THOUSAND FEET AGL. FLAT MOSTLY SCATTERED CUMULUS WITH BASES OF 3500-4500 FT AGL WILL DISSIPATE BY EARLY EVENING. WITH THIS RESIDUAL MOISTURE HOLDING IN THE LOW LEVELS WITH WEAK WINDS AND HIGH RELATIVE HUMIDITY OVERNIGHT... EXPECT AREAS OF FOG AND LOW CLOUDS TO FORM AFTER 06Z... MAINLY AT FAY WITH A LESSER CHANCE AT RWI/RDU. AT GSO/INT... INCREASING MID AND UPPER LEVEL CLOUDINESS AHEAD OF A COLD FRONT APPROACHING FROM THE NW WILL LIMIT RADIATIONAL COOLING AND HENCE LIMIT FOG AND LOW CLOUD DEVELOPMENT HERE. AFTER SUNRISE WEDNESDAY... A COLD FRONT WILL APPROACH FROM THE NW. THE LOW CLOUDS SHOULD MIX OUT QUICKLY WITH INCREASING SOUTHWEST SURFACE FLOW AHEAD OF THE COLD FRONT... AS MID CLOUDS (BASES ABOVE 5 KFT AGL) STEADILY INCREASE ACROSS THE AREA. A PREFRONTAL TROUGH WILL DROP SE THROUGH CENTRAL NC IN EARLY-MID AFTERNOON... SWITCHING SURFACE WINDS AROUND FROM SW TO W... WHILE THE FRONT ITSELF HOLDS OFF TO OUR NW UNTIL WEDNESDAY NIGHT. A FEW SPRINKLES OR SHOWERS ARE EXPECTED JUST AHEAD OF THE FRONT LOOKING BEYOND MID AFTERNOON WEDNESDAY... VFR CONDITIONS WILL RULE INTO FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. MVFR CIGS ARE POSSIBLE LATE FRIDAY NIGHT INTO SATURDAY AS THE FRONT TO OUR SOUTH TRIES TO HEAD BACK NORTH AS A WARM FRONT. A FEW SHOWERS OR STORMS ARE POSSIBLE SATURDAY INTO SUNDAY AS WE GET INTO THE WARM SECTOR AND DESTABILIZE. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...HARTFIELD NEAR TERM...HARTFIELD SHORT TERM...CBL LONG TERM...DJF AVIATION...HARTFIELD 000 FXUS62 KILM 071741 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 140 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH WEDNESDAY. A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN CHANCES. A TRANSITION TO A LATE SUMMER AIR-MASS THIS WEEKEND WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY WHICH MAY PERSIST INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM TUESDAY...SFC HIGH PRESSURE SETTLING OVER THE SOUTHEAST WITH RIDGE BUILDING ALOFT. PLENTY OF SUBSIDENCE AND DRY AIR IN PLACE THROUGH MID LEVELS...WILL KEEP A NICE LID ON ANY SHOWERS. EXPECT CU BUILDING AND SHOULD CONCENTRATE ITSELF ALONG SEA BREEZE BOUNDARY THROUGH THE AFTERNOON AND DISSIPATE MOST OTHER PLACES. OVERALL MOSTLY SUNNY AND RAIN FREE WEATHER EXPECTED. TEMPS WILL REACH THE MID TO UPPER 80S ALONG THE COAST TO THE LOWER 90S INLAND THIS AFTERNOON. CLEAR SKIES AND CALM WINDS WILL HELP TO PRODUCE SOME DECENT RADIATIONAL COOLING TONIGHT. ONSHORE COMPONENT TO FLOW WILL REMAIN VERY WEAK AS HIGH PRESSURE SETTLES OVERHEAD BUT WILL BE ADEQUATE ENOUGH THAT WHEN COMBINED WITH CLEAR SKIES AND LIGHT WINDS WILL PRODUCE AREAS OF FOG AFTER MIDNIGHT TONIGHT. SHOULD BE MORE PREVALENT OVER SC COAST WITH GREATER ON SHORE FLOW ON SOUTH SIDE OF HIGH AS IT DRIFTS SOUTHWARD. TEMPS OVERNIGHT SHOULD DROP TO MID 60S INLAND TO AROUND 70 AT THE COAST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3:00 AM TUESDAY...WESTERLY FLOW AT THE MID LEVELS WILL BUCKLE SLIGHTLY LATE WEDNESDAY AND INTO EARLY THURSDAY WHICH ALLOWS A COLD FRONT TO PUSH ACROSS THE AREA THURSDAY MORNING. THE NAM CONTINUES TO BE THE MOST AGGRESSIVE REGARDING POPS RELATIVELY SPEAKING AS A LITTLE LIGHT QPF IS GENERATED VIA LOW LEVEL FORCING. MAINTAINED THE SLIGHT CHANCE POPS FOR EARLY THURSDAY MAINLY ALONG THE COAST. GFS HOLDS THE FRONT CLOSER TO THE COAST DURING THE DAY AND WITH THE SEA BREEZE THIS MAY ALLOW SOME LATE DAY CONVECTION TO FIRE. CONFIDENCE NOT HIGH ENOUGH AT THIS POINT TO INTRODUCE POPS HOWEVER. CONTINUED TO LEAN TOWARD THE MET NUMBERS FOR TEMPERATURES. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3:00 AM TUESDAY...MID LEVEL PATTERN WILL TRANSITION FROM SOME MODEST AMPLIFICATION EARLY TO ZONAL BY SUNDAY AND WITH THE WEST TO EAST FLOW COMES LOWER CONFIDENCE THAN USUAL. INITIALLY A RESIDUAL BOUNDARY WILL GET SHUNTED SLIGHTLY FURTHER SOUTH FRIDAY AND EARLY SATURDAY AS A RIDGE AMPLIFIES ACROSS THE MIDWEST WITH HIGH PRESSURE PUSHING DOWN FROM THE NORTHEAST. CONTINUED TO ADVERTISE FRIDAY AS DRY. MAINTAINED POPS SATURDAY THROUGH MONDAY AS WEAK BERMUDA RIDGING DEVELOPS. ANOTHER FRONT MAY APPROACH THE AREA LATE MONDAY INTO TUESDAY BUT AS I MENTIONED EARLIER...CONFIDENCE IS LOW. NO CHANGES TO TEMPERATURE FORECAST. && .AVIATION /18Z TUESDAY THROUGH SATURDAY/... AS OF 18Z...VFR CONDITIONS ARE EXPECTED THROUGH THIS EVENING. ONLY AVIATION CONCERN WILL BE SOME LIGHT FOG TOWARD SUNRISE. ANY FOG FORMATION WILL BE SHALLOW...WITH FAIRLY STRONG WINDS AT 2K FEET WITH THE VERTICAL CHANGE IN HUMIDITY DECREASING. SOUTHERN TERMINALS STAND THE BEST CHANCE WITH THE LIGHTEST WINDS AT THE BOUNDARY LAYER. WEDNESDAY...FOG WILL MIX OUT TO UNRESTRICTED BY 13Z WITH ONLY SCATTERED CU EXPECTED. SOUTHEAST WINDS THIS AFTERNOON WILL DIMINISH FOR DIURNAL REASONS BY SUNSET. SOUTHWEST WINDS ON WEDNESDAY AHEAD OF A WEAK COLD FRONT THAT WILL DROP INTO THE REGION WEDNESDAY NIGHT. EXTENDED OUTLOOK...LOW CONFIDENCE IFR VISIBILITIES IN MORNING FOG EACH MORNING...MAINLY FLO/LBT. THERE WILL A POTENTIAL FOR ISOLATED SHOWERS/THUNDERSTORMS WEDNESDAY EVENING INTO THURSDAY MORNING ASSOCIATED WITH A COLD FRONT...AND AGAIN ON SATURDAY ASSOCIATED WITH A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM TUESDAY...VERY LIGHT ON SHORE FLOW WILL INCREASE SLIGHTLY WITH SEA BREEZE THIS AFTN MAINTAINING AROUND 10 KTS. SEAS WILL REMAIN 2 FT OR LESS MOST WATERS. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3:00 AM TUESDAY...RELATIVELY WEAK WINDS WEDNESDAY WILL INCREASE SLIGHTLY AS FRONT APPROACHES FROM THE NW LATE WEDNESDAY. NW FLOW ENSUES THURSDAY BUT IF THE GFS IS CORRECT...SEA BREEZE MAY QUICKLY VEER WINDS. NAM IS MORE AGGRESSIVE IN MAINTAINING NW FLOW. LOWER CONFIDENCE IN WIND DIRECTORIES AT THE END OF THE PERIOD. WAVEWATCH SEAS REMAIN CONSISTENT AROUND 2-3 FEET. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3:00 AM TUESDAY...NO CHANGES TO THE EXTENDED COASTAL WATERS FORECAST. NE WINDS INITIALLY WILL VEER TO SE BY THE END OF THE PERIOD AS WEAK BERMUDA HIGH PRESSURE SETS UP. THE LATEST WAVEWATCH GUIDANCE IS ADVERTISING A COUPLE OF RESPECTABLE SWELL COMPONENTS MAINLY FROM THE REMNANTS OF TROPICAL STORM GASTON. THIS SEEMS SUSPECT AS THE SYSTEM HAS OBVIOUSLY BEEN ERRATIC. HOWEVER SIGNIFICANT WAVE HEIGHTS REMAIN AROUND THREE FEET AND IF THE SWELL DOES INDEED OCCUR...IT MAY HAVE MORE IMPLICATIONS ON THE RIP CURRENT RISK THAN ANYTHING. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...SHK LONG TERM...SHK AVIATION...MRR 000 FXUS62 KRAH 071658 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 100 PM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TONIGHT. A WEAK COLD FRONT WILL CROSS THE AREA LATE WEDNESDAY. BEHIND THE FRONT...HIGH PRESSURE WILL GRADUALLY BUILD SOUTH INTO THE AREA DURING THE REST OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1020 AM TUESDAY... THROUGH TODAY: THE LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER NE NC RIDGING TOWARD THE SW THROUGH CENTRAL NC... CAPPED BY WEAK ANTICYCLONIC FLOW AT 925-850-700 MB. MORNING FOG AND STRATUS COVERING THE PIEDMONT HAS BEEN SLOW TO MIX OUT DUE TO THE WEAK WIND REGIME AND STABLE LOW LEVELS. WITH THE CAPPING INVERSION AROUND 800 MB... THIS LOW LEVEL MOISTURE SHOULD REMAIN POOLED AT THE TOP OF THE MIXED LAYER GIVEN THE LACK OF DISPERSION IN THE HORIZONTAL AND IN THE VERTICAL. WILL BUMP UP SKY COVER A BIT THROUGH TODAY... ESPECIALLY OVER THE NEXT FEW HOURS... BUT OVERALL THE FORECAST CLOUD TRENDS ARE GOOD. OTHERWISE... A DRY DAY WITH A STABLE PROFILE AND PLENTY OF DRY AIR NOTED ON WATER VAPOR IMAGERY AND BLENDED TPW IMAGERY. THICKNESSES THIS MORNING ARE SLIGHTLY HIGHER THAN YESTERDAY`S... CORRELATING TO HIGHS OF 89-94 FACTORING IN THE SLOWLY DISSIPATING STRATUS. -GIH THE COLD FRONT IS EXPECTED TO MOVE INTO CENTRAL/SOUTHERN APPALACHIANS BY AROUND DAYBREAK WEDNESDAY. MOISTURE/CLOUDS WILL BEGIN TO INCREASE OVER THE AREA...MAINLY OVER THE WESTERN PIEDMONT. MODELS SHOW GOOD MIXING IN THE 500 METERS...WITH A 30 KT H9 NOCTURNAL JET OVERSPREADING THE AREA EARLY WEDNESDAY MORNING SO DON`T EXPECT MUCH IN THE WAY OF FOG. THIS MECHANICAL MIXING ALONG WITH THE INCREASED IN MOISTURE/CLOUDS WILL MAKE IT CONSIDERABLY WARMER THAN PREVIOUS NIGHTS. OVERNIGHT LOWS IN THE MID TO UPPER 60S. -BL && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 230 AM TUESDAY... WEDNESDAY: TRAILING COLD FRONT ASSOCIATED WITH THE CLOSED LOW OVER SOUTHEASTERN CANADA WILL PUSH SOUTHEAST INTO THE AREA ON WEDNESDAY. WITH CENTRAL NC FAR REMOVED FROM THE PARENT LOW...ADEQUATE SHORTWAVE DYNAMICS AND LIFT IS NEITHER HIDE OR HAIR. THE NWLY LOW-LEVEL SUBSIDENT FLOW IN THE WAKE OF THE EASTWARD EXITING NOCTURNAL JET WEDNESDAY MORNING WILL WRING OUT THE SHALLOW MOISTURE ACCOMPANYING THE FRONT... RESULTING IN A VERY DRY SUB-CLOUD LAYER WEDNESDAY AFTERNOON. ADDITIONALLY A MID-LEVEL CAP RELUCTANT TO WEAKEN UNTIL LATE IN THE DAY IS EXPECTED TO KEEP THE AIRMASS CONVECTIVELY STABLE. WILL KEEP FORECAST DRY AS FAR AS MEASURABLE PRECIP...WITH ONLY TRACE AMOUNTS EXPECTED FROM SPRINKLES WEDNESDAY AFTERNOON. COMPRESSIONAL DOWNSLOPE FLOW COULD BE ENOUGH TO OFFSET THE COOLING FROM INCREASED CLOUD COVER AS THICKNESSES ARE FORECAST TO BE SIMILAR TO TUESDAY. HIGHS IN THE UPPER 80S TO LOWER 90S. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT: COLD FRONT IS EXPECTED TO SETTLE SOUTH AND EAST OF THE AREA WEDNESDAY EVENING WITH SKIES CLEARING FROM NORTHWEST TO SOUTHEAST AS WEAK CANADIAN HIGH PRESSURE WILL PUSH ANOTHER SURGE OF DRY AIR INTO NORTH CAROLINA FROM THE NORTH. THE BRUNT OF THE COOLER AIR HOWEVER REMAINS BOTTLED UP TO THE NORTH...WITH THICKNESSES ONLY A FEW METERS BELOW WEDNESDAYS READINGS. COULD SEE A FAIR AMOUNT OF HIGH CLOUDS ACROSS THE AREA ON THURSDAY AS UPPER JET DIVES SOUTHEAST OVER THE DELMARVA REGION...DOWN THE BACK-SIDE OF THE CLOSED LOW/UPPER TROUGH. SO UNDER MOSTLY/PARTLY SUNNY SKIES HIGHS THURSDAY WILL ONCE AGAIN RANGE IN THE UPPER 80S TO LOWER 90S. LOWS WEDNESDAY NIGHT IN THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. COOLER THURSDAY NIGHT...WITH LOWS IN THE UPPER 50S NORTH TO MID 60S SOUTH. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 255 AM TUESDAY... LONG-TERM GUIDANCE IS FAIRLY CONSISTENT BRINGING THE REMNANT SHORTWAVE OF HERMINE AROUND THE UPPER RIDGE AND TOWARD CENTRAL NORTH CAROLINA LATE FRIDAY AND ESPECIALLY FRIDAY NIGHT. THE PRIMARY QUESTION IS HOW TRAVEL THROUGH THE RIDGE WILL AFFECT THE INTENSITY... WITH THE LATEST GFS NOT TERRIBLY STRONG WITH THE WAVE BUT ABLE TO PROVIDE PRECIPITATION...AND THE CANADIAN APPARENTLY STRONGER BUT UNABLE TO GENERATE QPF FOR CENTRAL NORTH CAROLINA. WILL REVIEW THE 00Z ECMWF BEFORE MAKING A FINAL DECISION...BUT THE ONGOING FORECAST OF CHANCES OF SHOWERS WILL LIKELY BE KEPT INTACT AS THESE REMNANT TROPICAL WAVES OFTEN SEEM TO BE ABLE TO MAINTAIN SOME INTENSITY AND PROVIDE FOR AT LEAST SCATTERED SHOWERS AT TIMES BEFORE THEY COMPLETELY DIMINISH. IN THIS CASE...BELIEVE THE RIDGE WILL WEAKEN THE MID-LEVEL WAVE...BUT NOT ENOUGH TO LOWER CHANCES OF SHOWERS FROM THE FORECAST. GFSX MOS ENSEMBLE GUIDANCE IS ABOVE CLIMATOLOGY WITH REGARD TO CHANCES FOR SHOWERS SATURDAY THROUGH MONDAY. THE GFS PERSISTS A SURFACE WAVE IN THE FRONTAL ZONE JUST SOUTH OF THE STATE SATURDAY INTO SUNDAY...WITH THE CANADIAN SHOWING MORE SURFACE RIDGING SATURDAY BEFORE INTRODUCING MORE OF AN INVERTED TROUGH EXTENDING NORTH INTO THE STATE SUNDAY FROM LOW PRESSURE TO THE SOUTH. PRECIPITATION IS FORECAST MORE BY THE CANADIAN SUNDAY VERSUS SATURDAY...AND CURRENTLY THINK THIS IS THE MORE LIKELY SCENARIO IF THE TIMING OF THE MID-LEVEL WAVE LATE FRIDAY AND EARLY SATURDAY VERIFIES WITH SUBSIDENCE IN THE WAKE OF THE WAVE...FOLLOWED BY A QUICK RETURN OF SOME MOISTURE AND LIFT ON SUNDAY. GIVEN THE UNCERTAINTY WILL NOT REMOVE SLIGHT CHANCES FROM THE FORECAST SATURDAY...BUT OPTED TO RAISE POPS TO CHANCE FOR SUNDAY BASED ON THE CONSENSUS OF THE LONG-TERM GUIDANCE...HIGHEST ENSEMBLE MOS POPS FROM THE GFSX FOR SUNDAY...AND THE FACT THAT THIS IS THE THIRD RUN IN A ROW BY THE GFS WITH QPF ON SUNDAY. WITH MORE OF A NORTHWEST FLOW ALOFT DEVELOPING BY MONDAY...MADE THAT DAY DRY...AS BOTH THE 00Z GFS AND CANADIAN BRING A GOOD PUSH OF MEAN DRY AIR INTO THE STATE BY THEN. ONGOING FORECAST HIGH TEMPERATURES ARE MOSTLY AT OR BELOW OPERATIONAL MEX MOS...AND IN THE RANGE OF MOST OF THE GFSX MOS ENSEMBLE GUIDANCE WITH READINGS SOLIDLY IN THE 80S. AN ALTERNATIVE IS THAT ONE DAY...MOST LIKELY SUNDAY...COULD BE COOLER THAN FORECAST IF THERE IS ENOUGH CLOUDS AND PRECIPITATION... BUT CONFIDENCE IN THIS IS TOO LOW THIS FAR OUT TO MAKE ANY ADJUSTMENTS. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... AS OF 100 PM TUESDAY... THE MORNING FOG AND STRATUS WAS SLOW TO MIX OUT DUE TO THE CAPPING INVERSION ALOFT AND WEAK WINDS... RESULTING IN CLOUD BASES JUST IN THE LAST HOUR HAVING RISEN ABOVE 3 KFT. THESE CLOUDS SHOULD CONTINUE TO SLOWLY LIFT AND MIX... RESULTING IN VFR CONDITIONS AT ALL SITES LASTING THROUGH THE EVENING. A HIGH PRESSURE RIDGE HOLDS ACROSS CENTRAL NC... KEEPING WINDS VERY LIGHT AND VARIABLE FROM THE SURFACE UP THROUGH THE LOWEST FEW THOUSAND FEET AGL. FLAT MOSTLY SCATTERED CUMULUS WITH BASES OF 3500-4500 FT AGL WILL DISSIPATE BY EARLY EVENING. WITH THIS RESIDUAL MOISTURE HOLDING IN THE LOW LEVELS WITH WEAK WINDS AND HIGH RELATIVE HUMIDITY OVERNIGHT... EXPECT AREAS OF FOG AND LOW CLOUDS TO FORM AFTER 06Z... MAINLY AT FAY WITH A LESSER CHANCE AT RWI/RDU. AT GSO/INT... INCREASING MID AND UPPER LEVEL CLOUDINESS AHEAD OF A COLD FRONT APPROACHING FROM THE NW WILL LIMIT RADIATIONAL COOLING AND HENCE LIMIT FOG AND LOW CLOUD DEVELOPMENT HERE. AFTER SUNRISE WEDNESDAY... A COLD FRONT WILL APPROACH FROM THE NW. THE LOW CLOUDS SHOULD MIX OUT QUICKLY WITH INCREASING SOUTHWEST SURFACE FLOW AHEAD OF THE COLD FRONT... AS MID CLOUDS (BASES ABOVE 5 KFT AGL) STEADILY INCREASE ACROSS THE AREA. A PREFRONTAL TROUGH WILL DROP SE THROUGH CENTRAL NC IN EARLY-MID AFTERNOON... SWITCHING SURFACE WINDS AROUND FROM SW TO W... WHILE THE FRONT ITSELF HOLDS OFF TO OUR NW UNTIL WEDNESDAY NIGHT. A FEW SPRINKLES OR SHOWERS ARE EXPECTED JUST AHEAD OF THE FRONT LOOKING BEYOND MID AFTERNOON WEDNESDAY... VFR CONDITIONS WILL RULE INTO FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE NORTH. MVFR CIGS ARE POSSIBLE LATE FRIDAY NIGHT INTO SATURDAY AS THE FRONT TO OUR SOUTH TRIES TO HEAD BACK NORTH AS A WARM FRONT. A FEW SHOWERS OR STORMS ARE POSSIBLE SATURDAY INTO SUNDAY AS WE GET INTO THE WARM SECTOR AND DESTABILIZE. -GIH && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF/GIH NEAR TERM...HARTFIELD/CBL SHORT TERM...CBL LONG TERM...DJF AVIATION...HARTFIELD 000 FXUS62 KILM 071623 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1223 PM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH WEDNESDAY. A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN CHANCES. A TRANSITION TO A LATE SUMMER AIR-MASS THIS WEEKEND WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY WHICH MAY PERSIST INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM TUESDAY...SFC HIGH PRESSURE SETTLING OVER THE SOUTHEAST WITH RIDGE BUILDING ALOFT. PLENTY OF SUBSIDENCE AND DRY AIR IN PLACE THROUGH MID LEVELS...WILL KEEP A NICE LID ON ANY SHOWERS. EXPECT CU BUILDING AND SHOULD CONCENTRATE ITSELF ALONG SEA BREEZE BOUNDARY THROUGH THE AFTERNOON AND DISSIPATE MOST OTHER PLACES. OVERALL MOSTLY SUNNY AND RAIN FREE WEATHER EXPECTED. TEMPS WILL REACH THE MID TO UPPER 80S ALONG THE COAST TO THE LOWER 90S INLAND THIS AFTERNOON. CLEAR SKIES AND CALM WINDS WILL HELP TO PRODUCE SOME DECENT RADIATIONAL COOLING TONIGHT. ONSHORE COMPONENT TO FLOW WILL REMAIN VERY WEAK AS HIGH PRESSURE SETTLES OVERHEAD BUT WILL BE ADEQUATE ENOUGH THAT WHEN COMBINED WITH CLEAR SKIES AND LIGHT WINDS WILL PRODUCE AREAS OF FOG AFTER MIDNIGHT TONIGHT. SHOULD BE MORE PREVALENT OVER SC COAST WITH GREATER ON SHORE FLOW ON SOUTH SIDE OF HIGH AS IT DRIFTS SOUTHWARD. TEMPS OVERNIGHT SHOULD DROP TO MID 60S INLAND TO AROUND 70 AT THE COAST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3:00 AM TUESDAY...WESTERLY FLOW AT THE MID LEVELS WILL BUCKLE SLIGHTLY LATE WEDNESDAY AND INTO EARLY THURSDAY WHICH ALLOWS A COLD FRONT TO PUSH ACROSS THE AREA THURSDAY MORNING. THE NAM CONTINUES TO BE THE MOST AGGRESSIVE REGARDING POPS RELATIVELY SPEAKING AS A LITTLE LIGHT QPF IS GENERATED VIA LOW LEVEL FORCING. MAINTAINED THE SLIGHT CHANCE POPS FOR EARLY THURSDAY MAINLY ALONG THE COAST. GFS HOLDS THE FRONT CLOSER TO THE COAST DURING THE DAY AND WITH THE SEA BREEZE THIS MAY ALLOW SOME LATE DAY CONVECTION TO FIRE. CONFIDENCE NOT HIGH ENOUGH AT THIS POINT TO INTRODUCE POPS HOWEVER. CONTINUED TO LEAN TOWARD THE MET NUMBERS FOR TEMPERATURES. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3:00 AM TUESDAY...MID LEVEL PATTERN WILL TRANSITION FROM SOME MODEST AMPLIFICATION EARLY TO ZONAL BY SUNDAY AND WITH THE WEST TO EAST FLOW COMES LOWER CONFIDENCE THAN USUAL. INITIALLY A RESIDUAL BOUNDARY WILL GET SHUNTED SLIGHTLY FURTHER SOUTH FRIDAY AND EARLY SATURDAY AS A RIDGE AMPLIFIES ACROSS THE MIDWEST WITH HIGH PRESSURE PUSHING DOWN FROM THE NORTHEAST. CONTINUED TO ADVERTISE FRIDAY AS DRY. MAINTAINED POPS SATURDAY THROUGH MONDAY AS WEAK BERMUDA RIDGING DEVELOPS. ANOTHER FRONT MAY APPROACH THE AREA LATE MONDAY INTO TUESDAY BUT AS I MENTIONED EARLIER...CONFIDENCE IS LOW. NO CHANGES TO TEMPERATURE FORECAST. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...WATER VAPOR IMAGERY INDICATES GENERALLY DRY AIR ACROSS THE TERMINALS...BUT 11U-3.9U IMAGERY IS DETECTING SCATTERED TO BROKEN LOW/MID CLOUDS ALONG THE COAST. ISOLATED SHOWERS HAVE DEVELOPED IN THE COASTAL WATERS AT TIMES OVER PAST COUPLE OF HOURS ASSOCIATED WITH A SMALL AREA OF LOW LEVEL CONVERGENCE...REMNANTS OF AN OLD FRONTAL BOUNDARY AND...AND WERE MOVING INLAND JUST TO THE NORTHEAST OF THE CRE TERMINAL. THE VISIBILITY AT FLO WAS 5SM IN BR THIS MORNING. THE OTHER TERMINALS WERE VFR. EXPECT A RAPID IMPROVEMENT IN MVFR VISIBILITIES AT FLO TO VFR BY OR SHORTLY AFTER TAF ISSUANCE. SHOWER ACTIVITY NEAR CRE SHOULD DISSIPATE BY OR SHORTLY AFTER TAF ISSUANCE. A SUBSIDENCE CAP...DRY AIR...AND LACK OF LARGE SCALE LIFT...SHOULD INHIBIT ANY POTENTIAL SHOWER DEVELOPMENT THE REMAINDER OF THE DAY. LOW/MID CLOUDS ALONG THE COAST WILL PERSIST THROUGH THE DAY BUT EXPECT MAINLY SCATTERED COVERAGE. INLAND TERMINALS SHOULD HAVE MOSTLY SCATTERED CUMULUS 3-4K THROUGH THE DAY. WINDS TODAY WILL BE LIGHT NORTHEAST TO EAST BECOMING SOUTHEAST BY THIS AFTERNOON. BY SUNSET EXPECT WINDS TO BECOME LIGHT AND VARIABLE AT FLO/LBT AND AT THE COASTAL TERMINALS BY 02-04Z. WITH CLEAR SKIES AND LIGHT WINDS THERE WILL BE A FOG POTENTIAL AGAIN OVERNIGHT. THERE IS LOW CONFIDENCE IN ANY IFR DEVELOPING...SO WILL JUST INDICATE MVFR VISIBILITIES DEVELOPING IN THE PRE-DAWN HOURS AT ALL TERMINALS. EXTENDED OUTLOOK...LOW CONFIDENCE IFR VISIBILITIES IN MORNING FOG EACH MORNING...MAINLY FLO/LBT. THERE WILL A POTENTIAL FOR ISOLATED SHOWERS/THUNDERSTORMS WEDNESDAY AFTERNOON INTO THURSDAY MORNING ASSOCIATED WITH A COLD FRONT...AND AGAIN ON SATURDAY ASSOCIATED WITH A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM TUESDAY...VERY LIGHT ON SHORE FLOW WILL INCREASE SLIGHTLY WITH SEA BREEZE THIS AFTN MAINTAINING AROUND 10 KTS. SEAS WILL REMAIN 2 FT OR LESS MOST WATERS. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3:00 AM TUESDAY...RELATIVELY WEAK WINDS WEDNESDAY WILL INCREASE SLIGHTLY AS FRONT APPROACHES FROM THE NW LATE WEDNESDAY. NW FLOW ENSUES THURSDAY BUT IF THE GFS IS CORRECT...SEA BREEZE MAY QUICKLY VEER WINDS. NAM IS MORE AGGRESSIVE IN MAINTAINING NW FLOW. LOWER CONFIDENCE IN WIND DIRECTORIES AT THE END OF THE PERIOD. WAVEWATCH SEAS REMAIN CONSISTENT AROUND 2-3 FEET. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3:00 AM TUESDAY...NO CHANGES TO THE EXTENDED COASTAL WATERS FORECAST. NE WINDS INITIALLY WILL VEER TO SE BY THE END OF THE PERIOD AS WEAK BERMUDA HIGH PRESSURE SETS UP. THE LATEST WAVEWATCH GUIDANCE IS ADVERTISING A COUPLE OF RESPECTABLE SWELL COMPONENTS MAINLY FROM THE REMNANTS OF TROPICAL STORM GASTON. THIS SEEMS SUSPECT AS THE SYSTEM HAS OBVIOUSLY BEEN ERRATIC. HOWEVER SIGNIFICANT WAVE HEIGHTS REMAIN AROUND THREE FEET AND IF THE SWELL DOES INDEED OCCUR...IT MAY HAVE MORE IMPLICATIONS ON THE RIP CURRENT RISK THAN ANYTHING. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RGZ SHORT TERM...SHK LONG TERM...SHK AVIATION...MRR 000 FXUS62 KRAH 071424 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 1025 AM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TONIGHT. A WEAK COLD FRONT WILL CROSS THE AREA LATE WEDNESDAY. BEHIND THE FRONT...HIGH PRESSURE GRADUALLY BUILDS SOUTH INTO THE AREA DURING THE REST OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1020 AM TUESDAY... THROUGH TODAY: THE LATEST SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER NE NC RIDGING TOWARD THE SW THROUGH CENTRAL NC... CAPPED BY WEAK ANTICYCLONIC FLOW AT 925-850-700 MB. MORNING FOG AND STRATUS COVERING THE PIEDMONT HAS BEEN SLOW TO MIX OUT DUE TO THE WEAK WIND REGIME AND STABLE LOW LEVELS. WITH THE CAPPING INVERSION AROUND 800 MB... THIS LOW LEVEL MOISTURE SHOULD REMAIN POOLED AT THE TOP OF THE MIXED LAYER GIVEN THE LACK OF DISPERSION IN THE HORIZONTAL AND IN THE VERTICAL. WILL BUMP UP SKY COVER A BIT THROUGH TODAY... ESPECIALLY OVER THE NEXT FEW HOURS... BUT OVERALL THE FORECAST CLOUD TRENDS ARE GOOD. OTHERWISE... A DRY DAY WITH A STABLE PROFILE AND PLENTY OF DRY AIR NOTED ON WATER VAPOR IMAGERY AND BLENDED TPW IMAGERY. THICKNESSES THIS MORNING ARE SLIGHTLY HIGHER THAN YESTERDAY`S... CORRELATING TO HIGHS OF 89-94 FACTORING IN THE SLOWLY DISSIPATING STRATUS. -GIH THE COLD FRONT IS EXPECTED TO MOVE INTO CENTRAL/SOUTHERN APPALACHIANS BY AROUND DAYBREAK WEDNESDAY. MOISTURE/CLOUDS WILL BEGIN TO INCREASE OVER THE AREA...MAINLY OVER THE WESTERN PIEDMONT. MODELS SHOW GOOD MIXING IN THE 500 METERS...WITH A 30 KT H9 NOCTURNAL JET OVERSPREADING THE AREA EARLY WEDNESDAY MORNING SO DON`T EXPECT MUCH IN THE WAY OF FOG. THIS MECHANICAL MIXING ALONG WITH THE INCREASED IN MOISTURE/CLOUDS WILL MAKE IT CONSIDERABLY WARMER THAN PREVIOUS NIGHTS. OVERNIGHT LOWS IN THE MID TO UPPER 60S. -BL && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 230 AM TUESDAY... WEDNESDAY: TRAILING COLD FRONT ASSOCIATED WITH THE CLOSED LOW OVER SOUTHEASTERN CANADA WILL PUSH SOUTHEAST INTO THE AREA ON WEDNESDAY. WITH CENTRAL NC FAR REMOVED FROM THE PARENT LOW...ADEQUATE SHORTWAVE DYNAMICS AND LIFT IS NEITHER HIDE OR HAIR. THE NWLY LOW-LEVEL SUBSIDENT FLOW IN THE WAKE OF THE EASTWARD EXITING NOCTURNAL JET WEDNESDAY MORNING WILL WRING OUT THE SHALLOW MOISTURE ACCOMPANYING THE FRONT... RESULTING IN A VERY DRY SUB-CLOUD LAYER WEDNESDAY AFTERNOON. ADDITIONALLY A MID-LEVEL CAP RELUCTANT TO WEAKEN UNTIL LATE IN THE DAY IS EXPECTED TO KEEP THE AIRMASS CONVECTIVELY STABLE. WILL KEEP FORECAST DRY AS FAR AS MEASURABLE PRECIP...WITH ONLY TRACE AMOUNTS EXPECTED FROM SPRINKLES WEDNESDAY AFTERNOON. COMPRESSIONAL DOWNSLOPE FLOW COULD BE ENOUGH TO OFFSET THE COOLING FROM INCREASED CLOUD COVER AS THICKNESSES ARE FORECAST TO BE SIMILAR TO TUESDAY. HIGHS IN THE UPPER 80S TO LOWER 90S. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT: COLD FRONT IS EXPECTED TO SETTLE SOUTH AND EAST OF THE AREA WEDNESDAY EVENING WITH SKIES CLEARING FROM NORTHWEST TO SOUTHEAST AS WEAK CANADIAN HIGH PRESSURE WILL PUSH ANOTHER SURGE OF DRY AIR INTO NORTH CAROLINA FROM THE NORTH. THE BRUNT OF THE COOLER AIR HOWEVER REMAINS BOTTLED UP TO THE NORTH...WITH THICKNESSES ONLY A FEW METERS BELOW WEDNESDAYS READINGS. COULD SEE A FAIR AMOUNT OF HIGH CLOUDS ACROSS THE AREA ON THURSDAY AS UPPER JET DIVES SOUTHEAST OVER THE DELMARVA REGION...DOWN THE BACK-SIDE OF THE CLOSED LOW/UPPER TROUGH. SO UNDER MOSTLY/PARTLY SUNNY SKIES HIGHS THURSDAY WILL ONCE AGAIN RANGE IN THE UPPER 80S TO LOWER 90S. LOWS WEDNESDAY NIGHT IN THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. COOLER THURSDAY NIGHT...WITH LOWS IN THE UPPER 50S NORTH TO MID 60S SOUTH. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 255 AM TUESDAY... LONG-TERM GUIDANCE IS FAIRLY CONSISTENT BRINGING THE REMNANT SHORTWAVE OF HERMINE AROUND THE UPPER RIDGE AND TOWARD CENTRAL NORTH CAROLINA LATE FRIDAY AND ESPECIALLY FRIDAY NIGHT. THE PRIMARY QUESTION IS HOW TRAVEL THROUGH THE RIDGE WILL AFFECT THE INTENSITY... WITH THE LATEST GFS NOT TERRIBLY STRONG WITH THE WAVE BUT ABLE TO PROVIDE PRECIPITATION...AND THE CANADIAN APPARENTLY STRONGER BUT UNABLE TO GENERATE QPF FOR CENTRAL NORTH CAROLINA. WILL REVIEW THE 00Z ECMWF BEFORE MAKING A FINAL DECISION...BUT THE ONGOING FORECAST OF CHANCES OF SHOWERS WILL LIKELY BE KEPT INTACT AS THESE REMNANT TROPICAL WAVES OFTEN SEEM TO BE ABLE TO MAINTAIN SOME INTENSITY AND PROVIDE FOR AT LEAST SCATTERED SHOWERS AT TIMES BEFORE THEY COMPLETELY DIMINISH. IN THIS CASE...BELIEVE THE RIDGE WILL WEAKEN THE MID-LEVEL WAVE...BUT NOT ENOUGH TO LOWER CHANCES OF SHOWERS FROM THE FORECAST. GFSX MOS ENSEMBLE GUIDANCE IS ABOVE CLIMATOLOGY WITH REGARD TO CHANCES FOR SHOWERS SATURDAY THROUGH MONDAY. THE GFS PERSISTS A SURFACE WAVE IN THE FRONTAL ZONE JUST SOUTH OF THE STATE SATURDAY INTO SUNDAY...WITH THE CANADIAN SHOWING MORE SURFACE RIDGING SATURDAY BEFORE INTRODUCING MORE OF AN INVERTED TROUGH EXTENDING NORTH INTO THE STATE SUNDAY FROM LOW PRESSURE TO THE SOUTH. PRECIPITATION IS FORECAST MORE BY THE CANADIAN SUNDAY VERSUS SATURDAY...AND CURRENTLY THINK THIS IS THE MORE LIKELY SCENARIO IF THE TIMING OF THE MID-LEVEL WAVE LATE FRIDAY AND EARLY SATURDAY VERIFIES WITH SUBSIDENCE IN THE WAKE OF THE WAVE...FOLLOWED BY A QUICK RETURN OF SOME MOISTURE AND LIFT ON SUNDAY. GIVEN THE UNCERTAINTY WILL NOT REMOVE SLIGHT CHANCES FROM THE FORECAST SATURDAY...BUT OPTED TO RAISE POPS TO CHANCE FOR SUNDAY BASED ON THE CONSENSUS OF THE LONG-TERM GUIDANCE...HIGHEST ENSEMBLE MOS POPS FROM THE GFSX FOR SUNDAY...AND THE FACT THAT THIS IS THE THIRD RUN IN A ROW BY THE GFS WITH QPF ON SUNDAY. WITH MORE OF A NORTHWEST FLOW ALOFT DEVELOPING BY MONDAY...MADE THAT DAY DRY...AS BOTH THE 00Z GFS AND CANADIAN BRING A GOOD PUSH OF MEAN DRY AIR INTO THE STATE BY THEN. ONGOING FORECAST HIGH TEMPERATURES ARE MOSTLY AT OR BELOW OPERATIONAL MEX MOS...AND IN THE RANGE OF MOST OF THE GFSX MOS ENSEMBLE GUIDANCE WITH READINGS SOLIDLY IN THE 80S. AN ALTERNATIVE IS THAT ONE DAY...MOST LIKELY SUNDAY...COULD BE COOLER THAN FORECAST IF THERE IS ENOUGH CLOUDS AND PRECIPITATION... BUT CONFIDENCE IN THIS IS TOO LOW THIS FAR OUT TO MAKE ANY ADJUSTMENTS. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 700 AM TUESDAY... VFR CONDITIONS WILL CONTINUE TO BE THE RULE DURING THE 12Z VALID TAF PERIOD. AREAS OF LOW CLOUDS OVER THE WESTERN AND CENTRAL PIEDMONT SHOULD RAPIDLY MIX WITH SUNRISE. A 09Z AMDAR SOUNDING FROM KRDU SHOWS THE POTENTIAL FOR SCATTERED CU TO DEVELOP...AND A FEW...MOSTLY SOUTHWEST WIND GUSTS IN THE TEENS KTS FOR AN OBSERVATION OR TWO THROUGH MID-MORNING WITH INITIAL MIXING. HOWEVER...WITH MIXING...AND BASED ON THE MOISTURE TRACE ALOFT AND A GOOD CAP AT 700MB...CU SHOULD BECOME FLAT AND GENERALLY FEWER BY MID-AFTERNOON. THERE MAY BE MORE LOW CLOUDS LATE TONIGHT...JUST BEFORE THE END OF THE 12Z VALID TAF PERIOD...WITH SLIGHTLY STRONGER 925MB WINDS ALOFT AND A LOWER INVERSION HEIGHT WITH MOISTURE INCREASING SLIGHTLY. POTENTIAL FOR ANY FOG LIKELY A LITTLE GREATER AT KFAY AND KRWI WHERE SURFACE WINDS WILL BE LIGHTER LATE TONIGHT AND THERE WILL BE FEWER HIGH CLOUDS LONGER IN THE OVERNIGHT HOURS...BUT A COMBINATION OF A LIGHT WIND AND CIRRUS MOVING INTO CENTRAL NORTH CAROLINA SHOULD LIMIT FOG POTENTIAL AT OTHER TAF SITES. VFR CONDITIONS ARE ANTICIPATED OVERALL BEYOND THE 12Z VALID TAF PERIOD. A COLD FRONT MOVES THROUGH CENTRAL NORTH CAROLINA OVERNIGHT WEDNESDAY VEERING SURFACE WINDS. BASED ON A COMBINATION OF THE LATEST NAM AND GFS BUFR SOUNDINGS...THE NEXT BEST CHANCE OF IFR CONDITIONS FOR THE END OF THE WEEK AND THE START OF THE WEEKEND CONTINUES TO COME LATE SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF/GIH NEAR TERM...HARTFIELD/CBL SHORT TERM...CBL LONG TERM...DJF AVIATION...DJF 000 FXUS62 KMHX 071416 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 1016 AM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL EXTEND SOUTHWEST INTO THE AREA THROUGH TONIGHT. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. WEAK HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY. A WARM FRONT WILL LIFT NORTH THROUGH THE REGION ON SATURDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST SUNDAY AND MOVE INTO THE AREA MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 1015 AM TUESDAY...NO CHANGES TO THE CURRENT FORECAST. HIGH PRESSURE SURFACE AND ALOFT WILL CONTINUE TO PRODUCE WARM AND DRY WEATHER ACROSS NC TODAY. SUBSIDENCE WILL INHIBIT CLOUD FORMATION WITH FULL INSOLATION LEADING TO FURTHER AIRMASS MODIFICATION. GAVE SOME THOUGHT TO RAISING HIGHS INLAND TO LOWER 90S BUT DECIDED TO HOLD AT 90. PATCHY FOG/LOW STRATUS WILL BECOME MORE LIKELY LATE TONIGHT AS LOW LEVEL FLOW SHIFTS TO SOUTH AND DRAWS IN HIGHER DEW POINTS. THE MILDER BNDRY LAYER WILL RESULT IN TEMPS TONIGHT A BIT MILDER THAN PREV NITES WITH LOWS MAINLY MID 60S INLAND TO LOW 70S COAST. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... WITH THE APPROACH OF WEAK SHORT WAVE TROF...MID LEVEL RIDGE WILL BE SUPPRESSED SOUTH AND SFC HIGH PUSHED FARTHER OFFSHORE ON WEDNESDAY. HOWEVER A DEEPER/WARMER SW FLOW WILL RESULT IN HIGHS INTO THE LOWER 90S INLAND WED AFTN. WEAK FRONT WILL DROP SE THROUGH THE AREA WED NIGHT. DEEP MOISTURE AND MID LEVEL FORCING WILL BE LIMITED BUT LOW LEVEL CONVERGENCE ALONG THE BNDRY MAY SUPPORT ISOLD TO SCT CONVECTION. ALSO SREF PROBABILITIES FOR MEASURABLE PRECIP SUPPORT SLIGHT TO LOW CHC POPS WITH HIGHEST CHANCES CLOSER TO COAST. STABILITY INDICES ARE MARGINAL FOR TSTMS BUT HAVE A PRECAUTIONARY MENTION FOR NOW. && .LONG TERM /THURSDAY THROUGH MONDAY/... COLD FRONT STALLS TO THE S THU WITH HIGH PRES TO THE N. EXPECT DRY WX THU AND FRI WITH WARM/SEASONABLE TEMPS. REMNANTS OF HERMINE WILL EVENTUALLY GET CAUGHT UP IN THE MID LEVEL FLOW AND SHUD HELP ENHANCE PRECIP CHANCES DURING THE WEEKEND. SRT WAVES CROSSING IN ZONAL FLOW WILL LEAD TO CONT CHC POPS INTO MON AS COLD FRONT SAGS S INTO THE AREA. TEMPS WILL REMAIN NEAR TO SLIGHTLY ABV SEASONABLE NORMS. && .AVIATION /14Z TUESDAY THROUGH SATURDAY/... AS OF 1015 AM TUESDAY...VFR CONDITIONS WILL PREVAIL THROUGH EVENING AS HIGH PRESSURE CONTINUES TO PRODUCE DRY WEATHER ACROSS EASTERN NC. BEYOND 06Z WEDNESDAY...A FRONT WILL APPROACH THE REGION WEDNESDAY INTO THURSDAY. CLOUD COVER AND SW WINDS WILL BE ON THE INCREASE WEDNESDAY AFTERNOON AHEAD OF THE BOUNDARY. THE BEST CHANCE OF ANY PRECIPITATION WILL BE WEDNESDAY NIGHT INTO EARLY THURSDAY. HIGH PRESSURE WILL BUILD INTO THE REGION LATE THURSDAY BEFORE THE NEXT SYSTEM APPROACHES THIS WEEKEND. && .MARINE... AS OF 1015 AM TUESDAY...NO SIGNIFICANT CHANGES TO THE CURRENT FORECAST WITH ONLY MINOR TWEAKS TO WIND DIRECTION WITH FLOW TURNING FROM NE EARLY TO SE LATE. HIGH PRESSURE WILL CONTINUE TO PRODUCE LIGHT WINDS THROUGH TONIGHT WITH A 2 FT SWELL PERSISTING. PREVIOUS DISCUSSION...MODELS REMAIN CONSISTENT AND IN DECENT AGREEMENT...WITH NO MAJOR CHANGES TO PREVIOUS FCST. SPEEDS LESS THAN 15 KTS EXPECTED WITH GRADUALLY VEERING DIRECTION TODAY AND TONIGHT. STRONGEST WINDS DURING FCST PERIOD EXPECTED LATE WED INTO WED NIGHT AHEAD OF APPROACHING COLD FRONT WITH SPEEDS UP TO 20 KT. WINDS DIMINISH AFTER INITIAL POST-FRONTAL SURGE EARLY THU...THEN SECONDARY SURGE EXPECTED FRI. BLEND OF WW3...SWAN AND PREVIOUS FCST USED FOR SEAS DURING PERIOD. HEIGHTS UP TO 5 FT WITH PRE-FRONTAL WINDS WED NIGHT...AND AROUND 4 FT WITH SECONDARY POST-FRONTAL SURGE FRI. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...BTC/JME SHORT TERM...BTC LONG TERM...BTC/RF AVIATION...JBM/JME MARINE...JBM/JME 000 FXUS62 KILM 071152 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 752 AM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH WEDNESDAY. A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN CHANCES. A TRANSITION TO A LATE SUMMER AIR-MASS THIS WEEKEND WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY WHICH MAY PERSIST INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3:00 AM TUESDAY...REMNANTS OF OLD FRONTAL BOUNDARY BISECTING THE FORECAST AREA SHOWS UP MAINLY AS A MOISTURE DISCONTINUITY...WITH DEWPOINTS IN THE MID 60S TO THE NORTH...AND LOWER 70S TO THE SOUTH. FRONT WILL BE ONLY A MINOR PLAYER TODAY AS SURFACE RIDGE TO THE NORTH SETTLES OVER THE AREA TODAY...PUSHING THE FRONT OUT TO SEA AND OUT OF THE PICTURE. A WEAK COLD FRONT APPROACHING FROM THE NORTHWEST WILL ONLY HAVE REACHED THE APPALACHIANS BY THE END OF THE PERIOD. STABLE AND DRY AIR MASS WILL MAKE FOR A SUNNY DAY AFTER A BIT OF PATCHY FOG THIS MORNING. HOWEVER...DUE TO ONSHORE FLOW...THERE WILL BE ADEQUATE LOW LEVEL MOISTURE THAT WHEN COMBINED WITH CLEAR SKIES AND LIGHT WINDS WILL PRODUCE MORE EXTENSIVE AREAS OF FOG AFTER MIDNIGHT TONIGHT. GUIDANCE IN GOOD AGREEMENT WITH TEMPERATURES CLOSE TO YESTERDAYS VALUES...MID TO UPPER 80S ALONG THE COAST...LOWER 90S INLAND. LOWS FROM MID 60S INLAND TO AROUND 70 AT THE COAST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3:00 AM TUESDAY...WESTERLY FLOW AT THE MID LEVELS WILL BUCKLE SLIGHTLY LATE WEDNESDAY AND INTO EARLY THURSDAY WHICH ALLOWS A COLD FRONT TO PUSH ACROSS THE AREA THURSDAY MORNING. THE NAM CONTINUES TO BE THE MOST AGGRESSIVE REGARDING POPS RELATIVELY SPEAKING AS A LITTLE LIGHT QPF IS GENERATED VIA LOW LEVEL FORCING. MAINTAINED THE SLIGHT CHANCE POPS FOR EARLY THURSDAY MAINLY ALONG THE COAST. GFS HOLDS THE FRONT CLOSER TO THE COAST DURING THE DAY AND WITH THE SEA BREEZE THIS MAY ALLOW SOME LATE DAY CONVECTION TO FIRE. CONFIDENCE NOT HIGH ENOUGH AT THIS POINT TO INTRODUCE POPS HOWEVER. CONTINUED TO LEAN TOWARD THE MET NUMBERS FOR TEMPERATURES. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3:00 AM TUESDAY...MID LEVEL PATTERN WILL TRANSITION FROM SOME MODEST AMPLIFICATION EARLY TO ZONAL BY SUNDAY AND WITH THE WEST TO EAST FLOW COMES LOWER CONFIDENCE THAN USUAL. INITIALLY A RESIDUAL BOUNDARY WILL GET SHUNTED SLIGHTLY FURTHER SOUTH FRIDAY AND EARLY SATURDAY AS A RIDGE AMPLIFIES ACROSS THE MIDWEST WITH HIGH PRESSURE PUSHING DOWN FROM THE NORTHEAST. CONTINUED TO ADVERTISE FRIDAY AS DRY. MAINTAINED POPS SATURDAY THROUGH MONDAY AS WEAK BERMUDA RIDGING DEVELOPS. ANOTHER FRONT MAY APPROACH THE AREA LATE MONDAY INTO TUESDAY BUT AS I MENTIONED EARLIER...CONFIDENCE IS LOW. NO CHANGES TO TEMPERATURE FORECAST. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 12Z...WATER VAPOR IMAGERY INDICATES GENERALLY DRY AIR ACROSS THE TERMINALS...BUT 11U-3.9U IMAGERY IS DETECTING SCATTERED TO BROKEN LOW/MID CLOUDS ALONG THE COAST. ISOLATED SHOWERS HAVE DEVELOPED IN THE COASTAL WATERS AT TIMES OVER PAST COUPLE OF HOURS ASSOCIATED WITH A SMALL AREA OF LOW LEVEL CONVERGENCE...REMNANTS OF AN OLD FRONTAL BOUNDARY AND...AND WERE MOVING INLAND JUST TO THE NORTHEAST OF THE CRE TERMINAL. THE VISIBILITY AT FLO WAS 5SM IN BR THIS MORNING. THE OTHER TERMINALS WERE VFR. EXPECT A RAPID IMPROVEMENT IN MVFR VISIBILITIES AT FLO TO VFR BY OR SHORTLY AFTER TAF ISSUANCE. SHOWER ACTIVITY NEAR CRE SHOULD DISSIPATE BY OR SHORTLY AFTER TAF ISSUANCE. A SUBSIDENCE CAP...DRY AIR...AND LACK OF LARGE SCALE LIFT...SHOULD INHIBIT ANY POTENTIAL SHOWER DEVELOPMENT THE REMAINDER OF THE DAY. LOW/MID CLOUDS ALONG THE COAST WILL PERSIST THROUGH THE DAY BUT EXPECT MAINLY SCATTERED COVERAGE. INLAND TERMINALS SHOULD HAVE MOSTLY SCATTERED CUMULUS 3-4K THROUGH THE DAY. WINDS TODAY WILL BE LIGHT NORTHEAST TO EAST BECOMING SOUTHEAST BY THIS AFTERNOON. BY SUNSET EXPECT WINDS TO BECOME LIGHT AND VARIABLE AT FLO/LBT AND AT THE COASTAL TERMINALS BY 02-04Z. WITH CLEAR SKIES AND LIGHT WINDS THERE WILL BE A FOG POTENTIAL AGAIN OVERNIGHT. THERE IS LOW CONFIDENCE IN ANY IFR DEVELOPING...SO WILL JUST INDICATE MVFR VISIBILITIES DEVELOPING IN THE PRE-DAWN HOURS AT ALL TERMINALS. EXTENDED OUTLOOK...LOW CONFIDENCE IFR VISIBILITIES IN MORNING FOG EACH MORNING...MAINLY FLO/LBT. THERE WILL A POTENTIAL FOR ISOLATED SHOWERS/THUNDERSTORMS WEDNESDAY AFTERNOON INTO THURSDAY MORNING ASSOCIATED WITH A COLD FRONT...AND AGAIN ON SATURDAY ASSOCIATED WITH A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3:00 AM TUESDAY...LIGHT WINDS OVER THE WATERS TODAY AS HIGH PRESSURE SETTLES OVER THE REGION. SEAS WILL NOT STRAY FAR FROM PRESENT 2 FT RANGE. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3:00 AM TUESDAY...RELATIVELY WEAK WINDS WEDNESDAY WILL INCREASE SLIGHTLY AS FRONT APPROACHES FROM THE NW LATE WEDNESDAY. NW FLOW ENSUES THURSDAY BUT IF THE GFS IS CORRECT...SEA BREEZE MAY QUICKLY VEER WINDS. NAM IS MORE AGGRESSIVE IN MAINTAINING NW FLOW. LOWER CONFIDENCE IN WIND DIRECTORIES AT THE END OF THE PERIOD. WAVEWATCH SEAS REMAIN CONSISTENT AROUND 2-3 FEET. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3:00 AM TUESDAY...NO CHANGES TO THE EXTENDED COASTAL WATERS FORECAST. NE WINDS INITIALLY WILL VEER TO SE BY THE END OF THE PERIOD AS WEAK BERMUDA HIGH PRESSURE SETS UP. THE LATEST WAVEWATCH GUIDANCE IS ADVERTISING A COUPLE OF RESPECTABLE SWELL COMPONENTS MAINLY FROM THE REMNANTS OF TROPICAL STORM GASTON. THIS SEEMS SUSPECT AS THE SYSTEM HAS OBVIOUSLY BEEN ERRATIC. HOWEVER SIGNIFICANT WAVE HEIGHTS REMAIN AROUND THREE FEET AND IF THE SWELL DOES INDEED OCCUR...IT MAY HAVE MORE IMPLICATIONS ON THE RIP CURRENT RISK THAN ANYTHING. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...REK SHORT TERM...SHK LONG TERM...SHK AVIATION...MRR 000 FXUS62 KRAH 071102 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 702 AM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TODAY. A WEAK COLD FRONT CROSSES THE AREA LATE WEDNESDAY. BEHIND THE FRONT...HIGH PRESSURE GRADUALLY BUILDS SOUTH INTO THE AREA DURING THE REST OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 AM TUESDAY... CLOSED MID AND UPPER LEVEL WAVE OVER THE UPPER MIDWEST WILL MOVE EAST ACROSS THE GREAT LAKES AND INTO SOUTHEASTERN CANADA...FLATTENING THE UPPER ANTICYCLONE THAT RESIDES OVER THE SOUTHEASTERN US. MEANWHILE... HERMINE WILL DRIFT NORTH-NORTHWEST ACROSS NORTHEASTERN MEXICO AND INTO SOUTH TEXAS. CENTRAL NC WILL REMAIN WITHIN THE VERY WARM AND VERY STABLE REGIME UNDERNEATH THE FLATTENING MID LEVEL RIDGE AXIS AS THE DRY AIR ALOFT ENCOMPASSES THE AREA. IT WILL BE HARD PRESSED TO SEE LITTLE IN THE WAY OF CLOUDINESS WITH A FEW CU TRYING TO DEVELOP ACROSS THE WEST THIS AFTERNOON AS SWLY RETURN FLOW DEVELOPS LATE IN THE DAY AS THE COLD FRONT PUSHES EAST INTO THE OHIO AND TENNESSEE VALLEYS. LOW-LEVEL THICKNESSES INCREASE ACCORDINGLY...CREEPING UP 10 METERS TO AROUND 1420M...WHICH WILL SUPPORT AFTERNOON HIGHS OF 89 TO 94. THE COLD FRONT IS EXPECTED TO MOVE INTO CENTRAL/SOUTHERN APPALACHIANS BY AROUND DAYBREAK WEDNESDAY. MOISTURE/CLOUDS WILL BEGIN TO INCREASE OVER THE AREA...MAINLY OVER THE WESTERN PIEDMONT. MODELS SHOW GOOD MIXING IN THE 500 METERS...WITH A 30 KT H9 NOCTURNAL JET OVERSPREADING THE AREA EARLY WEDNESDAY MORNING SO DON`T EXPECT MUCH IN THE WAY OF FOG. THIS MECHANICAL MIXING ALONG WITH THE INCREASED IN MOISTURE/CLOUDS WILL MAKE IT CONSIDERABLY WARMER THAN PREVIOUS NIGHTS. OVERNIGHT LOWS IN THE MID TO UPPER 60S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 230 AM TUESDAY... WEDNESDAY: TRAILING COLD FRONT ASSOCIATED WITH THE CLOSED LOW OVER SOUTHEASTERN CANADA WILL PUSH SOUTHEAST INTO THE AREA ON WEDNESDAY. WITH CENTRAL NC FAR REMOVED FROM THE PARENT LOW...ADEQUATE SHORTWAVE DYNAMICS AND LIFT IS NEITHER HIDE OR HAIR. THE NWLY LOW-LEVEL SUBSIDENT FLOW IN THE WAKE OF THE EASTWARD EXITING NOCTURNAL JET WEDNESDAY MORNING WILL WRING OUT THE SHALLOW MOISTURE ACCOMPANYING THE FRONT... RESULTING IN A VERY DRY SUB-CLOUD LAYER WEDNESDAY AFTERNOON. ADDITIONALLY A MID-LEVEL CAP RELUCTANT TO WEAKEN UNTIL LATE IN THE DAY IS EXPECTED TO KEEP THE AIRMASS CONVECTIVELY STABLE. WILL KEEP FORECAST DRY AS FAR AS MEASURABLE PRECIP...WITH ONLY TRACE AMOUNTS EXPECTED FROM SPRINKLES WEDNESDAY AFTERNOON. COMPRESSIONAL DOWNSLOPE FLOW COULD BE ENOUGH TO OFFSET THE COOLING FROM INCREASED CLOUD COVER AS THICKNESSES ARE FORECAST TO BE SIMILAR TO TUESDAY. HIGHS IN THE UPPER 80S TO LOWER 90S. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT: COLD FRONT IS EXPECTED TO SETTLE SOUTH AND EAST OF THE AREA WEDNESDAY EVENING WITH SKIES CLEARING FROM NORTHWEST TO SOUTHEAST AS WEAK CANADIAN HIGH PRESSURE WILL PUSH ANOTHER SURGE OF DRY AIR INTO NORTH CAROLINA FROM THE NORTH. THE BRUNT OF THE COOLER AIR HOWEVER REMAINS BOTTLED UP TO THE NORTH...WITH THICKNESSES ONLY A FEW METERS BELOW WEDNESDAYS READINGS. COULD SEE A FAIR AMOUNT OF HIGH CLOUDS ACROSS THE AREA ON THURSDAY AS UPPER JET DIVES SOUTHEAST OVER THE DELMARVA REGION...DOWN THE BACK-SIDE OF THE CLOSED LOW/UPPER TROUGH. SO UNDER MOSTLY/PARTLY SUNNY SKIES HIGHS THURSDAY WILL ONCE AGAIN RANGE IN THE UPPER 80S TO LOWER 90S. LOWS WEDNESDAY NIGHT IN THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. COOLER THURSDAY NIGHT...WITH LOWS IN THE UPPER 50S NORTH TO MID 60S SOUTH. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 255 AM TUESDAY... LONG-TERM GUIDANCE IS FAIRLY CONSISTENT BRINGING THE REMNANT SHORTWAVE OF HERMINE AROUND THE UPPER RIDGE AND TOWARD CENTRAL NORTH CAROLINA LATE FRIDAY AND ESPECIALLY FRIDAY NIGHT. THE PRIMARY QUESTION IS HOW TRAVEL THROUGH THE RIDGE WILL AFFECT THE INTENSITY... WITH THE LATEST GFS NOT TERRIBLY STRONG WITH THE WAVE BUT ABLE TO PROVIDE PRECIPITATION...AND THE CANADIAN APPARENTLY STRONGER BUT UNABLE TO GENERATE QPF FOR CENTRAL NORTH CAROLINA. WILL REVIEW THE 00Z ECMWF BEFORE MAKING A FINAL DECISION...BUT THE ONGOING FORECAST OF CHANCES OF SHOWERS WILL LIKELY BE KEPT INTACT AS THESE REMNANT TROPICAL WAVES OFTEN SEEM TO BE ABLE TO MAINTAIN SOME INTENSITY AND PROVIDE FOR AT LEAST SCATTERED SHOWERS AT TIMES BEFORE THEY COMPLETELY DIMINISH. IN THIS CASE...BELIEVE THE RIDGE WILL WEAKEN THE MID-LEVEL WAVE...BUT NOT ENOUGH TO LOWER CHANCES OF SHOWERS FROM THE FORECAST. GFSX MOS ENSEMBLE GUIDANCE IS ABOVE CLIMATOLOGY WITH REGARD TO CHANCES FOR SHOWERS SATURDAY THROUGH MONDAY. THE GFS PERSISTS A SURFACE WAVE IN THE FRONTAL ZONE JUST SOUTH OF THE STATE SATURDAY INTO SUNDAY...WITH THE CANADIAN SHOWING MORE SURFACE RIDGING SATURDAY BEFORE INTRODUCING MORE OF AN INVERTED TROUGH EXTENDING NORTH INTO THE STATE SUNDAY FROM LOW PRESSURE TO THE SOUTH. PRECIPITATION IS FORECAST MORE BY THE CANADIAN SUNDAY VERSUS SATURDAY...AND CURRENTLY THINK THIS IS THE MORE LIKELY SCENARIO IF THE TIMING OF THE MID-LEVEL WAVE LATE FRIDAY AND EARLY SATURDAY VERIFIES WITH SUBSIDENCE IN THE WAKE OF THE WAVE...FOLLOWED BY A QUICK RETURN OF SOME MOISTURE AND LIFT ON SUNDAY. GIVEN THE UNCERTAINTY WILL NOT REMOVE SLIGHT CHANCES FROM THE FORECAST SATURDAY...BUT OPTED TO RAISE POPS TO CHANCE FOR SUNDAY BASED ON THE CONSENSUS OF THE LONG-TERM GUIDANCE...HIGHEST ENSEMBLE MOS POPS FROM THE GFSX FOR SUNDAY...AND THE FACT THAT THIS IS THE THIRD RUN IN A ROW BY THE GFS WITH QPF ON SUNDAY. WITH MORE OF A NORTHWEST FLOW ALOFT DEVELOPING BY MONDAY...MADE THAT DAY DRY...AS BOTH THE 00Z GFS AND CANADIAN BRING A GOOD PUSH OF MEAN DRY AIR INTO THE STATE BY THEN. ONGOING FORECAST HIGH TEMPERATURES ARE MOSTLY AT OR BELOW OPERATIONAL MEX MOS...AND IN THE RANGE OF MOST OF THE GFSX MOS ENSEMBLE GUIDANCE WITH READINGS SOLIDLY IN THE 80S. AN ALTERNATIVE IS THAT ONE DAY...MOST LIKELY SUNDAY...COULD BE COOLER THAN FORECAST IF THERE IS ENOUGH CLOUDS AND PRECIPITATION... BUT CONFIDENCE IN THIS IS TOO LOW THIS FAR OUT TO MAKE ANY ADJUSTMENTS. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... AS OF 700 AM TUESDAY... VFR CONDITIONS WILL CONTINUE TO BE THE RULE DURING THE 12Z VALID TAF PERIOD. AREAS OF LOW CLOUDS OVER THE WESTERN AND CENTRAL PIEDMONT SHOULD RAPIDLY MIX WITH SUNRISE. A 09Z AMDAR SOUNDING FROM KRDU SHOWS THE POTENTIAL FOR SCATTERED CU TO DEVELOP...AND A FEW...MOSTLY SOUTHWEST WIND GUSTS IN THE TEENS KTS FOR AN OBSERVATION OR TWO THROUGH MID-MORNING WITH INITIAL MIXING. HOWEVER...WITH MIXING...AND BASED ON THE MOISTURE TRACE ALOFT AND A GOOD CAP AT 700MB...CU SHOULD BECOME FLAT AND GENERALLY FEWER BY MID-AFTERNOON. THERE MAY BE MORE LOW CLOUDS LATE TONIGHT...JUST BEFORE THE END OF THE 12Z VALID TAF PERIOD...WITH SLIGHTLY STRONGER 925MB WINDS ALOFT AND A LOWER INVERSION HEIGHT WITH MOISTURE INCREASING SLIGHTLY. POTENTIAL FOR ANY FOG LIKELY A LITTLE GREATER AT KFAY AND KRWI WHERE SURFACE WINDS WILL BE LIGHTER LATE TONIGHT AND THERE WILL BE FEWER HIGH CLOUDS LONGER IN THE OVERNIGHT HOURS...BUT A COMBINATION OF A LIGHT WIND AND CIRRUS MOVING INTO CENTRAL NORTH CAROLINA SHOULD LIMIT FOG POTENTIAL AT OTHER TAF SITES. VFR CONDITIONS ARE ANTICIPATED OVERALL BEYOND THE 12Z VALID TAF PERIOD. A COLD FRONT MOVES THROUGH CENTRAL NORTH CAROLINA OVERNIGHT WEDNESDAY VEERING SURFACE WINDS. BASED ON A COMBINATION OF THE LATEST NAM AND GFS BUFR SOUNDINGS...THE NEXT BEST CHANCE OF IFR CONDITIONS FOR THE END OF THE WEEK AND THE START OF THE WEEKEND CONTINUES TO COME LATE SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...CBL SHORT TERM...CBL LONG TERM...DJF AVIATION...DJF 000 FXUS62 KMHX 070814 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 410 AM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL EXTEND SOUTHWEST INTO THE AREA THROUGH TONIGHT. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. WEAK HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY. A WARM FRONT WILL LIFT NORTH THROUGH THE REGION ON SATURDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST SUNDAY AND MOVE INTO THE AREA MONDAY. && .NEAR TERM /THROUGH TONIGHT/... OFFSHORE SFC HIGH PRES EXTENDS SW OVR THE AREA AS MID LEVEL RIDGE CENTERED OVR THE TNVLY THIS MORN BUILDS INTO THE REGION THRU TONIGHT. EXPECT LTL IN THE WAY OF CLOUDINESS IN THE DRY/SUBSIDENT AIRMASS. FULL INSOLATION YIELDS HIGH TEMPS RANGING FROM NEAR 90F INLAND TO MID 80S IMMEDIATE COAST. PATCHY FOG/LOW STRATUS WILL BECOME MORE LIKELY LATE TONIGHT AS LOW LEVEL FLOW SHIFTS TO SOUTH AND DRAWS IN HIGHER DEW POINTS. THE MILDER BNDRY LAYER WILL RESULT IN TEMPS TONIGHT A BIT MILDER THAN PREV NITES WITH LOWS MAINLY MID 60S INLAND TO LOW 70S COAST. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... WITH THE APPROACH OF WEAK SHORT WAVE TROF...MID LEVEL RIDGE WILL BE SUPPRESSED SOUTH AND SFC HIGH PUSHED FARTHER OFFSHORE ON WEDNESDAY. HOWEVER A DEEPER/WARMER SW FLOW WILL RESULT IN HIGHS INTO THE LOWER 90S INLAND WED AFTN. WEAK FRONT WILL DROP SE THROUGH THE AREA WED NIGHT. DEEP MOISTURE AND MID LEVEL FORCING WILL BE LIMITED BUT LOW LEVEL CONVERGENCE ALONG THE BNDRY MAY SUPPORT ISOLD TO SCT CONVECTION. ALSO SREF PROBABILITIES FOR MEASURABLE PRECIP SUPPORT SLIGHT TO LOW CHC POPS WITH HIGHEST CHANCES CLOSER TO COAST. STABILITY INDICES ARE MARGINAL FOR TSTMS BUT HAVE A PRECAUTIONARY MENTION FOR NOW. && .LONG TERM /THURSDAY THROUGH MONDAY/... COLD FRONT STALLS TO THE S THU WITH HIGH PRES TO THE N. EXPECT DRY WX THU AND FRI WITH WARM/SEASONABLE TEMPS. REMNANTS OF HERMINE WILL EVENTUALLY GET CAUGHT UP IN THE MID LEVEL FLOW AND SHUD HELP ENHANCE PRECIP CHANCES DURING THE WEEKEND. SRT WAVES CROSSING IN ZONAL FLOW WILL LEAD TO CONT CHC POPS INTO MON AS COLD FRONT SAGS S INTO THE AREA. TEMPS WILL REMAIN NEAR TO SLIGHTLY ABV SEASONABLE NORMS. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... AS OF 07Z TUE...WITH SFC HIGH STILL EXTENDING OVER AREA AND HIGHER DEW PTS THAN MON MORNING...WENT WITH MOS GDNC FOR PERIOD OF IFR VSBYS IN FOG AT KPGV AND KOAJ AND MVFR AT KEWN AND KISO...MAINLY 09Z-12Z. VFR REST OF DAY WITH HIGH PRES SFC AND ALOFT. SOME CU/SCU PSBL IN AFTN SIMILAR TO MON. BEYOND 06Z WEDNESDAY...A FRONT WILL APPROACH THE REGION WEDNESDAY INTO THURSDAY. CLOUD COVER AND SW WINDS WILL BE ON THE INCREASE WEDNESDAY AFTERNOON AHEAD OF THE BOUNDARY. THE BEST CHANCE OF ANY PRECIPITATION WILL BE WEDNESDAY NIGHT INTO EARLY THURSDAY. HIGH PRESSURE WILL BUILD INTO THE REGION LATE THURSDAY BEFORE THE NEXT SYSTEM APPROACHES THIS WEEKEND. && .MARINE... AS OF 4 AM TUE...MODELS REMAIN CONSISTENT AND IN DECENT AGREEMENT...WITH NO MAJOR CHANGES TO PREVIOUS FCST. SPEEDS LESS THAN 15 KTS EXPECTED WITH GRADUALLY VEERING DIRECTION TODAY AND TONIGHT. STRONGEST WINDS DURING FCST PERIOD EXPECTED LATE WED INTO WED NIGHT AHEAD OF APPROACHING COLD FRONT WITH SPEEDS UP TO 20 KT. WINDS DIMINISH AFTER INITIAL POST-FRONTAL SURGE EARLY THU...THEN SECONDARY SURGE EXPECTED FRI. BLEND OF WW3...SWAN AND PREVIOUS FCST USED FOR SEAS DURING PERIOD. HEIGHTS UP TO 5 FT WITH PRE-FRONTAL WINDS WED NIGHT...AND AROUND 4 FT WITH SECONDARY POST-FRONTAL SURGE FRI. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...BTC SHORT TERM...BTC LONG TERM...BTC/RF AVIATION...JBM MARINE...JBM 000 FXUS62 KMHX 070701 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 301 AM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE CENTERED OFF THE MID ATLANTIC COAST WILL EXTEND SOUTHWEST INTO THE AREA THROUGH TONIGHT. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. WEAK HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY. A WARM FRONT WILL LIFT NORTH THROUGH THE REGION ON SATURDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST SUNDAY AND MOVE INTO THE AREA MONDAY. && .NEAR TERM /THROUGH TONIGHT/... OFFSHORE SFC HIGH PRES EXTENDS SW OVR THE AREA AS MID LEVEL RIDGE CENTERED OVR THE TNVLY THIS MORN BUILDS INTO THE REGION THRU TONIGHT. EXPECT LTL IN THE WAY OF CLOUDINESS IN THE DRY/SUBSIDENT AIRMASS. FULL INSOLATION YIELDS HIGH TEMPS RANGING FROM NEAR 90F INLAND TO MID 80S IMMEDIATE COAST. PATCHY FOG/LOW STRATUS WILL BECOME MORE LIKELY LATE TONIGHT AS LOW LEVEL FLOW SHIFTS TO SOUTH AND DRAWS IN HIGHER DEW POINTS. THE MILDER BNDRY LAYER WILL RESULT IN TEMPS TONIGHT A BIT MILDER THAN PREV NITES WITH LOWS MAINLY MID 60S INLAND TO LOW 70S COAST. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... WITH THE APPROACH OF WEAK SHORT WAVE TROF...MID LEVEL RIDGE WILL BE SUPPRESSED SOUTH AND SFC HIGH PUSHED FARTHER OFFSHORE ON WEDNESDAY. HOWEVER A DEEPER/WARMER SW FLOW WILL RESULT IN HIGHS INTO THE LOWER 90S INLAND WED AFTN. WEAK FRONT WILL DROP SE THROUGH THE AREA WED NIGHT. DEEP MOISTURE AND MID LEVEL FORCING WILL BE LIMITED BUT LOW LEVEL CONVERGENCE ALONG THE BNDRY MAY SUPPORT ISOLD TO SCT CONVECTION. ALSO SREF PROBABILITIES FOR MEASURABLE PRECIP SUPPORT SLIGHT TO LOW CHC POPS WITH HIGHEST CHANCES CLOSER TO COAST. STABILITY INDICES ARE MARGINAL FOR TSTMS BUT HAVE A PRECAUTIONARY MENTION FOR NOW. && .LONG TERM /THURSDAY THROUGH MONDAY/... COLD FRONT STALLS TO THE S THU WITH HIGH PRES TO THE N. EXPECT DRY WX THU AND FRI WITH WARM/SEASONABLE TEMPS. REMNANTS OF HERMINE WILL EVENTUALLY GET CAUGHT UP IN THE MID LEVEL FLOW AND SHUD HELP ENHANCE PRECIP CHANCES DURING THE WEEKEND. SRT WAVES CROSSING IN ZONAL FLOW WILL LEAD TO CONT CHC POPS INTO MON AS COLD FRONT SAGS S INTO THE AREA. TEMPS WILL REMAIN NEAR TO SLIGHTLY ABV SEASONABLE NORMS. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... AS OF 00Z TUE...HIGH PRESSURE CURRENTLY IN CONTROL OVER MUCH OF THE MID- ATLANTIC REGION WILL GIVE WAY TO MAINLY CLEAR SKIES THROUGHOUT THE TAF PERIOD. WITH LIGHT WINDS AND CLEAR SKIES OVERNIGHT...ANTICIPATE SOME PATCHY FOG TO DEVELOP BETWEEN 06-12Z TUESDAY. ANY LOW LEVEL MOISTURE IN PLACE EARLY TUESDAY WILL QUICKLY DISSIPATE AFTER SUNRISE AS BOUNDARY LAYER MIXING INCREASES. SIMILAR TO TODAY...EXPECT CLEAR SKIES AND WINDS VEERING NE TO SE AROUND 5-8KTS TUESDAY. BEYOND 18Z TUESDAY...A FRONT WILL APPROACH THE REGION WEDNESDAY INTO THURSDAY. CLOUD COVER AND SW WINDS WILL BE ON THE INCREASE WEDNESDAY AFTERNOON AHEAD OF THE BOUNDARY. THE BEST CHANCE OF ANY PRECIPITATION WILL BE WEDNESDAY NIGHT INTO EARLY THURSDAY. HIGH PRESSURE WILL BUILD INTO THE REGION LATE THURSDAY BEFORE THE NEXT SYSTEM APPROACHES THIS WEEKEND. && .MARINE... AS OF 745 PM MON...DECREASED WIND SPEEDS OVER THE SOUNDS AND WATERS NORTH OF OREGON INLET TO BETTER MATCH CURRENT OBSERVATIONS. NO OTHER CHANGES MADE. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...BTC SHORT TERM...BTC LONG TERM...BTC/RF AVIATION...BM/LP MARINE...HSA 000 FXUS62 KILM 070700 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 300 AM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH WEDNESDAY. A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN CHANCES. A TRANSITION TO A LATE SUMMER AIR-MASS THIS WEEKEND WILL BRING INCREASED SHOWER AND THUNDERSTORM ACTIVITY WHICH MAY PERSIST INTO EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3:00 AM TUESDAY...REMNANTS OF OLD FRONTAL BOUNDARY BISECTING THE FORECAST AREA SHOWS UP MAINLY AS A MOISTURE DISCONTINUITY...WITH DEWPOINTS IN THE MID 60S TO THE NORTH...AND LOWER 70S TO THE SOUTH. FRONT WILL BE ONLY A MINOR PLAYER TODAY AS SURFACE RIDGE TO THE NORTH SETTLES OVER THE AREA TODAY....PUSHING THE FRONT OUT TO SEA AND OUT OF THE PICTURE. A WEAK COLD FRONT APPROACHING FROM THE NORTHWEST WILL ONLY HAVE REACHED THE APPALACHIANS BY THE END OF THE PERIOD. STABLE AND DRY AIRMASS WILL MAKE FOR A SUNNY DAY AFTER A BIT OF PATCHY FOG THIS MORNING. HOWEVER...DUE TO ONSHORE FLOW...THERE WILL BE ADEQUATE LOW LEVEL MOISTURE THAT WHEN COMBINED WITH CLEAR SKIES AND LIGHT WINDS WILL PRODUCE MORE EXTENSIVE AREAS OF FOG AFTER MIDNIGHT TONIGHT. GUIDANCE IN GOOD AGREEMENT WITH TEMPERATURES CLOSE TO YESTERDAYS VALUES...MID TO UPPER 80S ALONG THE COAST...LOWER 90S INLAND. LOWS FROM MID 60S INLAND TO AROUND 70 AT THE COAST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3:00 AM TUESDAY...WESTERLY FLOW AT THE MID LEVELS WILL BUCKLE SLIGHTLY LATE WEDNESDAY AND INTO EARLY THURSDAY WHICH ALLOWS A COLD FRONT TO PUSH ACROSS THE AREA THURSDAY MORNING. THE NAM CONTINUES TO BE THE MOST AGGRESSIVE REGARDING POPS RELATIVELY SPEAKING AS A LITTLE LIGHT QPF IS GENERATED VIA LOW LEVEL FORCING. MAINTAINED THE SLIGHT CHANCE POPS FOR EARLY THURSDAY MAINLY ALONG THE COAST. GFS HOLDS THE FRONT CLOSER TO THE COAST DURING THE DAY AND WITH THE SEA BREEZE THIS MAY ALLOW SOME LATE DAY CONVECTION TO FIRE. CONFIDENCE NOT HIGH ENOUGH AT THIS POINT TO INTRODUCE POPS HOWEVER. CONTINUED TO LEAN TOWARD THE MET NUMBERS FOR TEMPERATURES. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 3:00 AM TUESDAY...MID LEVEL PATTERN WILL TRANSITION FROM SOME MODEST AMPLIFICATION EARLY TO ZONAL BY SUNDAY AND WITH THE WEST TO EAST FLOW COMES LOWER CONFIDENCE THAN USUAL. INITIALLY A RESIDUAL BOUNDARY WILL GET SHUNTED SLIGHTLY FURTHER SOUTH FRIDAY AND EARLY SATURDAY AS A RIDGE AMPLIFIES ACROSS THE MIDWEST WITH HIGH PRESSURE PUSHING DOWN FROM THE NORTHEAST. CONTINUED TO ADVERTISE FRIDAY AS DRY. MAINTAINED POPS SATURDAY THROUGH MONDAY AS WEAK BERMUDA RIDGING DEVELOPS. ANOTHER FRONT MAY APPROACH THE AREA LATE MONDAY INTO TUESDAY BUT AS I MENTIONED EARLIER...CONFIDENCE IS LOW. NO CHANGES TO TEMPERATURE FORECAST. && .AVIATION /07Z TUESDAY THROUGH SATURDAY/... AS OF 06Z...MODERATE CONFIDENCE FORECAST THROUGH THE VALID PERIOD DUE TO POTENTIAL FOG AND/OR STRATUS OVERNIGHT. CLOUD COVER HAS MOSTLY ERODED OVER THE AREA...WITH THE EXCEPTION BEING AT THE MYRTLES WHERE SOME STRATOCU FOCUSED ALONG AN OLD OUTFLOW BOUNDARY CONTINUES TO DEVELOP AND MOVE ONSHORE. WINDS STAYED ELEVATED LONGER THAN PREVIOUSLY ANTICIPATED...SO HAVE SLOWED ONSET OF FOG OVERNIGHT. AT THE SAME TIME...THE LONGER DURATION SE FLOW HAS ADVECTED EVEN MORE MOISTURE INTO THE SURFACE LAYER...SO ONCE WINDS DO GO CALM FOG LOOKS LIKE A GOOD BET...ESPECIALLY INLAND. FOR THIS REASON HAVE PREDOMINATE IFR FOG AT BOTH INLAND TERMINALS TOWARDS TUESDAY MORNING. THE LONGER DURATION WINDS HAVE INHIBITED EARLIER RADIATIONAL COOLING...SO LIFR NOT ANTICIPATED...BUT SIGNIFICANT RESTRICTIONS APPEAR LIKELY FOR AT LEAST A SHORT TIME TOWARDS SUNRISE. AT THE COAST...CONFIDENCE IS LOWER IN FOG DUE TO CONTINUED STRATOCU AND THE WINDS PREVIOUSLY MENTIONED. BUFR PROFILES INDICATING THE DEVELOPMENT OF A WEAK...BUT STILL PRESENT...LLJ JUST ABOVE THE B/L. THIS MAY PRODUCE MORE OF A STRATUS ISSUE...AND BUFR PROFILES ARE INDICATING MORE STRATUS THAN FOG AT THE COAST. HAVE CHOSEN TO USE TEMPO BKN MVFR CIGS AT THE MYRTLES WHERE TD/S ARE IN THE 70S...COMBINED WITH MVFR VSBYS. WOULD NOT BE SURPRISED IF VSBYS STAY UNRESTRICTED HOWEVER...AND MAY NEED TO ISSUE SOME AMENDMENTS OVERNIGHT. HAVE MVFR FOG AT ILM WITH SCT AT MVFR LEVELS TO CONTINUE TO REFLECT POTENTIAL STRATUS THERE. AFTER SUNRISE TUESDAY FOG WILL BURN OFF AND SOME EARLY MORNING STRATOCU WILL LIKELY DEVELOP. AS RIDGE ALOFT FINALLY BUILDS OVERHEAD...SUBSIDENCE CAP WILL HELP ERODE/INHIBIT MUCH CLOUD DEVELOPMENT DURING THE AFTN...AND ANTICIPATE NEARLY CLOUDLESS SKY CONDITIONS NEAR THE COAST. INLAND MAY SEE SOME AFTN DIURNAL CU WITH SIGNIFICANT AFTN HEATING. WINDS THROUGH THE DAY WILL VEER NE TO SE...AND INCREASE TO AROUND 10 KTS. CLOUD COVER WILL AGAIN RAPIDLY ERODE WITH LOSS OF HEATING TUESDAY NIGHT. WINDS WILL DROP TO NEAR CALM AND SOME STRATOCU WILL AGAIN AFFECT THE COAST BY THE END OF THIS VALID PERIOD. EXTENDED OUTLOOK...MORNING FOG POSSIBLE EACH MORNING. COLD FRONT WILL APPROACH THE AREA THURSDAY WITH A SLIGHT CHANCE OF SHOWERS. MORE SHOWERS ARE POSSIBLE SATURDAY WITH THE ADVANCE OF A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3:00 AM TUESDAY...LIGHT WINDS OVER THE WATERS TODAY AS HIGH PRESSURE SETTLES OVER THE REGION. SEAS WILL NOT STRAY FAR FROM PRESENT 2 FT RANGE. SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3:00 AM TUESDAY...RELATIVELY WEAK WINDS WEDNESDAY WILL INCREASE SLIGHTLY AS FRONT APPROACHES FROM THE NW LATE WEDNESDAY. NW FLOW ENSUES THURSDAY BUT IF THE GFS IS CORRECT...SEA BREEZE MAY QUICKLY VEER WINDS. NAM IS MORE AGRESSIVE IN MAINTAINING NW FLOW. LOWER CONFIDENSE IN WIND DIRECTRIONS AT THE END OF THE PERIOD. WAVEWATCH SEAS REMAIN CONSISTENT AROUND 2-3 FEET. LONG TERM /FRIDAY THROUGH SATURDAY/... AS OF 3:00 AM TUESDAY...NO CHANGES TO THE EXTENDED COASTAL WATERS FORECAST. NE WINDS INITIALLY WILL VEER TO SE BY THE END OF THE PERIOD AS WEAK BERMUDA HIGH PRESSURE SETS UP. THE LATEST WAVEWATCH GUIDANCE IS ADVERTISING A COUPLE OF RESPECTABLE SWELL COMPONENTS MAINLY FROM THE REMNANTS OF TROPICAL STORM GASTON. THIS SEEMS SUSPECT AS THE SYSTEM HAS OBVIOUSLY BEEN ERRATIC. HOWEVER SIGNIFICANT WAVE HEIGHTS REMAIN AROUND THREE FEET AND IF THE SWELL DOES INDEED OCCUR...IT MAY HAVE MORE IMPLICATIONS ON THE RIP CURRENT RISK THAN ANYTHING. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...REK SHORT TERM...SHK LONG TERM...SHK AVIATION...JDW 000 FXUS62 KRAH 070655 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 255 AM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TODAY. A WEAK COLD FRONT CROSSES THE AREA LATE WEDNESDAY. BEHIND THE FRONT...HIGH PRESSURE GRADUALLY BUILDS SOUTH INTO THE AREA DURING THE REST OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 AM TUESDAY... CLOSED MID AND UPPER LEVEL WAVE OVER THE UPPER MIDWEST WILL MOVE EAST ACROSS THE GREAT LAKES AND INTO SOUTHEASTERN CANADA...FLATTENING THE UPPER ANTICYCLONE THAT RESIDES OVER THE SOUTHEASTERN US. MEANWHILE... HERMINE WILL DRIFT NORTH-NORTHWEST ACROSS NORTHEASTERN MEXICO AND INTO SOUTH TEXAS. CENTRAL NC WILL REMAIN WITHIN THE VERY WARM AND VERY STABLE REGIME UNDERNEATH THE FLATTENING MID LEVEL RIDGE AXIS AS THE DRY AIR ALOFT ENCOMPASSES THE AREA. IT WILL BE HARD PRESSED TO SEE LITTLE IN THE WAY OF CLOUDINESS WITH A FEW CU TRYING TO DEVELOP ACROSS THE WEST THIS AFTERNOON AS SWLY RETURN FLOW DEVELOPS LATE IN THE DAY AS THE COLD FRONT PUSHES EAST INTO THE OHIO AND TENNESSEE VALLEYS. LOW-LEVEL THICKNESSES INCREASE ACCORDINGLY...CREEPING UP 10 METERS TO AROUND 1420M...WHICH WILL SUPPORT AFTERNOON HIGHS OF 89 TO 94. THE COLD FRONT IS EXPECTED TO MOVE INTO CENTRAL/SOUTHERN APPALACHIANS BY AROUND DAYBREAK WEDNESDAY. MOISTURE/CLOUDS WILL BEGIN TO INCREASE OVER THE AREA...MAINLY OVER THE WESTERN PIEDMONT. MODELS SHOW GOOD MIXING IN THE 500 METERS...WITH A 30 KT H9 NOCTURNAL JET OVERSPREADING THE AREA EARLY WEDNESDAY MORNING SO DON`T EXPECT MUCH IN THE WAY OF FOG. THIS MECHANICAL MIXING ALONG WITH THE INCREASED IN MOISTURE/CLOUDS WILL MAKE IT CONSIDERABLY WARMER THAN PREVIOUS NIGHTS. OVERNIGHT LOWS IN THE MID TO UPPER 60S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 230 AM TUESDAY... WEDNESDAY: TRAILING COLD FRONT ASSOCIATED WITH THE CLOSED LOW OVER SOUTHEASTERN CANADA WILL PUSH SOUTHEAST INTO THE AREA ON WEDNESDAY. WITH CENTRAL NC FAR REMOVED FROM THE PARENT LOW...ADEQUATE SHORTWAVE DYNAMICS AND LIFT IS NEITHER HIDE OR HAIR. THE NWLY LOW-LEVEL SUBSIDENT FLOW IN THE WAKE OF THE EASTWARD EXITING NOCTURNAL JET WEDNESDAY MORNING WILL WRING OUT THE SHALLOW MOISTURE ACCOMPANYING THE FRONT... RESULTING IN A VERY DRY SUB-CLOUD LAYER WEDNESDAY AFTERNOON. ADDITIONALLY A MID-LEVEL CAP RELUCTANT TO WEAKEN UNTIL LATE IN THE DAY IS EXPECTED TO KEEP THE AIRMASS CONVECTIVELY STABLE. WILL KEEP FORECAST DRY AS FAR AS MEASURABLE PRECIP...WITH ONLY TRACE AMOUNTS EXPECTED FROM SPRINKLES WEDNESDAY AFTERNOON. COMPRESSIONAL DOWNSLOPE FLOW COULD BE ENOUGH TO OFFSET THE COOLING FROM INCREASED CLOUD COVER AS THICKNESSES ARE FORECAST TO BE SIMILAR TO TUESDAY. HIGHS IN THE UPPER 80S TO LOWER 90S. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT: COLD FRONT IS EXPECTED TO SETTLE SOUTH AND EAST OF THE AREA WEDNESDAY EVENING WITH SKIES CLEARING FROM NORTHWEST TO SOUTHEAST AS WEAK CANADIAN HIGH PRESSURE WILL PUSH ANOTHER SURGE OF DRY AIR INTO NORTH CAROLINA FROM THE NORTH. THE BRUNT OF THE COOLER AIR HOWEVER REMAINS BOTTLED UP TO THE NORTH...WITH THICKNESSES ONLY A FEW METERS BELOW WEDNESDAYS READINGS. COULD SEE A FAIR AMOUNT OF HIGH CLOUDS ACROSS THE AREA ON THURSDAY AS UPPER JET DIVES SOUTHEAST OVER THE DELMARVA REGION...DOWN THE BACK-SIDE OF THE CLOSED LOW/UPPER TROUGH. SO UNDER MOSTLY/PARTLY SUNNY SKIES HIGHS THURSDAY WILL ONCE AGAIN RANGE IN THE UPPER 80S TO LOWER 90S. LOWS WEDNESDAY NIGHT IN THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. COOLER THURSDAY NIGHT...WITH LOWS IN THE UPPER 50S NORTH TO MID 60S SOUTH. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 255 AM TUESDAY... LONG-TERM GUIDANCE IS FAIRLY CONSISTENT BRINGING THE REMNANT SHORTWAVE OF HERMINE AROUND THE UPPER RIDGE AND TOWARD CENTRAL NORTH CAROLINA LATE FRIDAY AND ESPECIALLY FRIDAY NIGHT. THE PRIMARY QUESTION IS HOW TRAVEL THROUGH THE RIDGE WILL AFFECT THE INTENSITY... WITH THE LATEST GFS NOT TERRIBLY STRONG WITH THE WAVE BUT ABLE TO PROVIDE PRECIPITATION...AND THE CANADIAN APPARENTLY STRONGER BUT UNABLE TO GENERATE QPF FOR CENTRAL NORTH CAROLINA. WILL REVIEW THE 00Z ECMWF BEFORE MAKING A FINAL DECISION...BUT THE ONGOING FORECAST OF CHANCES OF SHOWERS WILL LIKELY BE KEPT INTACT AS THESE REMNANT TROPICAL WAVES OFTEN SEEM TO BE ABLE TO MAINTAIN SOME INTENSITY AND PROVIDE FOR AT LEAST SCATTERED SHOWERS AT TIMES BEFORE THEY COMPLETELY DIMINISH. IN THIS CASE...BELIEVE THE RIDGE WILL WEAKEN THE MID-LEVEL WAVE...BUT NOT ENOUGH TO LOWER CHANCES OF SHOWERS FROM THE FORECAST. GFSX MOS ENSEMBLE GUIDANCE IS ABOVE CLIMATOLOGY WITH REGARD TO CHANCES FOR SHOWERS SATURDAY THROUGH MONDAY. THE GFS PERSISTS A SURFACE WAVE IN THE FRONTAL ZONE JUST SOUTH OF THE STATE SATURDAY INTO SUNDAY...WITH THE CANADIAN SHOWING MORE SURFACE RIDGING SATURDAY BEFORE INTRODUCING MORE OF AN INVERTED TROUGH EXTENDING NORTH INTO THE STATE SUNDAY FROM LOW PRESSURE TO THE SOUTH. PRECIPITATION IS FORECAST MORE BY THE CANADIAN SUNDAY VERSUS SATURDAY...AND CURRENTLY THINK THIS IS THE MORE LIKELY SCENARIO IF THE TIMING OF THE MID-LEVEL WAVE LATE FRIDAY AND EARLY SATURDAY VERIFIES WITH SUBSIDENCE IN THE WAKE OF THE WAVE...FOLLOWED BY A QUICK RETURN OF SOME MOISTURE AND LIFT ON SUNDAY. GIVEN THE UNCERTAINTY WILL NOT REMOVE SLIGHT CHANCES FROM THE FORECAST SATURDAY...BUT OPTED TO RAISE POPS TO CHANCE FOR SUNDAY BASED ON THE CONSENSUS OF THE LONG-TERM GUIDANCE...HIGHEST ENSEMBLE MOS POPS FROM THE GFSX FOR SUNDAY...AND THE FACT THAT THIS IS THE THIRD RUN IN A ROW BY THE GFS WITH QPF ON SUNDAY. WITH MORE OF A NORTHWEST FLOW ALOFT DEVELOPING BY MONDAY...MADE THAT DAY DRY...AS BOTH THE 00Z GFS AND CANADIAN BRING A GOOD PUSH OF MEAN DRY AIR INTO THE STATE BY THEN. ONGOING FORECAST HIGH TEMPERATURES ARE MOSTLY AT OR BELOW OPERATIONAL MEX MOS...AND IN THE RANGE OF MOST OF THE GFSX MOS ENSEMBLE GUIDANCE WITH READINGS SOLIDLY IN THE 80S. AN ALTERNATIVE IS THAT ONE DAY...MOST LIKELY SUNDAY...COULD BE COOLER THAN FORECAST IF THERE IS ENOUGH CLOUDS AND PRECIPITATION... BUT CONFIDENCE IN THIS IS TOO LOW THIS FAR OUT TO MAKE ANY ADJUSTMENTS. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 145 AM TUESDAY... VFR CONDITIONS WILL CONTINUE TO BE THE RULE DURING THE 06Z VALID TAF PERIOD. THE LATEST GUIDANCE HAS BACKED OFF SOMEWHAT WITH THE POTENTIAL FOR FOG AND/OR STRATUS...WITH MODEL SOUNDINGS SOMEWHAT DRY IN THE BOUNDARY LAYER...MOS GUIDANCE HIGHER WITH VISIBILITIES AND CEILINGS AROUND 12Z ESPECIALLY AT KFAY AND KRWI...AND SREF ENSEMBLE GUIDANCE WITH RELATIVELY LOW CHANCES FOR IFR CONDITIONS. HAVE FORECAST CATEGORICAL OR TEMPO MVFR FOG AROUND SUNRISE AT KRDU...KFAY AND KRWI...WITH TEMPO IFR AT THE LATTER TWO...WITH CONFIDENCE OF LIFR CONDITIONS AT PRESENT NOT HIGH. MAY BE A LITTLE BETTER POTENTIAL FOR STRATUS LATE TONIGHT...JUST BEYOND THE 06Z VALID TAF PERIOD...WITH SLIGHTLY STRONGER 925MB WINDS ALOFT AND A LOWER INVERSION HEIGHT WITH MOISTURE INCREASING SLIGHTLY. POTENTIAL FOR FOG LIKELY A LITTLE GREATER AT KRWI WHERE SURFACE WINDS WILL BE LIGHTER LATE TONIGHT...BUT A COMBINATION OF A LIGHT WIND AND CIRRUS MOVING INTO CENTRAL NORTH CAROLINA SHOULD LIMIT FOG POTENTIAL AT OTHER TAF SITES. VFR CONDITIONS ARE ANTICIPATED OVERALL BEYOND THE 06Z VALID TAF PERIOD. A COLD FRONT MOVES THROUGH CENTRAL NORTH CAROLINA OVERNIGHT WEDNESDAY VEERING SURFACE WINDS. BASED ON A COMBINATION OF THE LATEST NAM AND GFS BUFR SOUNDINGS...THE NEXT BEST CHANCE OF IFR CONDITIONS FOR THE END OF THE WEEK AND THE START OF THE WEEKEND COMES LATE SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...CBL SHORT TERM...CBL LONG TERM...DJF AVIATION...DJF 000 FXUS62 KRAH 070645 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 245 AM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TODAY. A WEAK COLD FRONT CROSSES THE AREA LATE WEDNESDAY. BEHIND THE FRONT...HIGH PRESSURE GRADUALLY BUILDS SOUTH INTO THE AREA DURING THE REST OF THE WORK WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 AM TUESDAY... CLOSED MID AND UPPER LEVEL WAVE OVER THE UPPER MIDWEST WILL MOVE EAST ACROSS THE GREAT LAKES AND INTO SOUTHEASTERN CANADA...FLATTENING THE UPPER ANTICYCLONE THAT RESIDES OVER THE SOUTHEASTERN US. MEANWHILE... HERMINE WILL DRIFT NORTH-NORTHWEST ACROSS NORTHEASTERN MEXICO AND INTO SOUTH TEXAS. CENTRAL NC WILL REMAIN WITHIN THE VERY WARM AND VERY STABLE REGIME UNDERNEATH THE FLATTENING MID LEVEL RIDGE AXIS AS THE DRY AIR ALOFT ENCOMPASSES THE AREA. IT WILL BE HARD PRESSED TO SEE LITTLE IN THE WAY OF CLOUDINESS WITH A FEW CU TRYING TO DEVELOP ACROSS THE WEST THIS AFTERNOON AS SWLY RETURN FLOW DEVELOPS LATE IN THE DAY AS THE COLD FRONT PUSHES EAST INTO THE OHIO AND TENNESSEE VALLEYS. LOW-LEVEL THICKNESSES INCREASE ACCORDINGLY...CREEPING UP 10 METERS TO AROUND 1420M...WHICH WILL SUPPORT AFTERNOON HIGHS OF 89 TO 94. THE COLD FRONT IS EXPECTED TO MOVE INTO CENTRAL/SOUTHERN APPALACHIANS BY AROUND DAYBREAK WEDNESDAY. MOISTURE/CLOUDS WILL BEGIN TO INCREASE OVER THE AREA...MAINLY OVER THE WESTERN PIEDMONT. MODELS SHOW GOOD MIXING IN THE 500 METERS...WITH A 30 KT H9 NOCTURNAL JET OVERSPREADING THE AREA EARLY WEDNESDAY MORNING SO DON`T EXPECT MUCH IN THE WAY OF FOG. THIS MECHANICAL MIXING ALONG WITH THE INCREASED IN MOISTURE/CLOUDS WILL MAKE IT CONSIDERABLY WARMER THAN PREVIOUS NIGHTS. OVERNIGHT LOWS IN THE MID TO UPPER 60S. .SHORT TERM/WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 230 AM TUESDAY... WEDNESDAY: TRAILING COLD FRONT ASSOCIATED WITH THE CLOSED LOW OVER SOUTHEASTERN CANADA WILL PUSH SOUTHEAST INTO THE AREA ON WEDNESDAY. WITH CENTRAL NC FAR REMOVED FROM THE PARENT LOW...ADEQUATE SHORTWAVE DYNAMICS AND LIFT IS NEITHER HIDE OR HAIR. THE NWLY LOW-LEVEL SUBSIDENT FLOW IN THE WAKE OF THE EASTWARD EXITING NOCTURNAL JET WEDNESDAY MORNING WILL WRING OUT THE SHALLOW MOISTURE ACCOMPANYING THE FRONT... RESULTING IN A VERY DRY SUB-CLOUD LAYER WEDNESDAY AFTERNOON. ADDITIONALLY A MID-LEVEL CAP RELUCTANT TO WEAKEN UNTIL LATE IN THE DAY IS EXPECTED TO KEEP THE AIRMASS CONVECTIVELY STABLE. WILL KEEP FORECAST DRY AS FAR AS MEASURABLE PRECIP...WITH ONLY TRACE AMOUNTS EXPECTED FROM SPRINKLES WEDNESDAY AFTERNOON. COMPRESSIONAL DOWNSLOPE FLOW COULD BE ENOUGH TO OFFSET THE COOLING FROM INCREASED CLOUD COVER AS THICKNESSES ARE FORECAST TO BE SIMILAR TO TUESDAY. HIGHS IN THE UPPER 80S TO LOWER 90S. WEDNESDAY NIGHT THROUGH THURSDAY NIGHT: COLD FRONT IS EXPECTED TO SETTLE SOUTH AND EAST OF THE AREA WEDNESDAY EVENING WITH SKIES CLEARING FROM NORTHWEST TO SOUTHEAST AS WEAK CANADIAN HIGH PRESSURE WILL PUSH ANOTHER SURGE OF DRY AIR INTO NORTH CAROLINA FROM THE NORTH. THE BRUNT OF THE COOLER AIR HOWEVER REMAINS BOTTLED UP TO THE NORTH...WITH THICKNESSES ONLY A FEW METERS BELOW WEDNESDAYS READINGS. COULD SEE A FAIR AMOUNT OF HIGH CLOUDS ACROSS THE AREA ON THURSDAY AS UPPER JET DIVES SOUTHEAST OVER THE DELMARVA REGION...DOWN THE BACK-SIDE OF THE CLOSED LOW/UPPER TROUGH. SO UNDER MOSTLY/PARTLY SUNNY SKIES HIGHS THURSDAY WILL ONCE AGAIN RANGE IN THE UPPER 80S TO LOWER 90S. LOWS WEDNESDAY NIGHT IN THE LOWER 60S NORTHWEST TO UPPER 60S SOUTHEAST. COOLER THURSDAY NIGHT...WITH LOWS IN THE UPPER 50S NORTH TO MID 60S SOUTH. && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 235 PM MONDAY... FOR FRIDAY THROUGH SATURDAY: THE FRONT TO OUR SSW TRIES TO HEAD BACK NORTHEAST AS A WARM FRONT ON FRIDAY ACCORDING TO THE LATEST GFS/ECMWF. BUT AS THE MID LEVEL VORTEX SITS AND SPINS OVER NOVA SCOTIA WITH TROUGHING ENCOMPASSING MOST OF THE EASTERN SEABOARD AND WESTERN ATLANTIC... THE BLOCKING PATTERN SHOULD HELP KEEP THE SURFACE RIDGE DOMINANT THROUGH FRIDAY NIGHT. BUT THE ECMWF (AND TO A LESSER DEGREE THE GFS) INDICATES 850 MILLIBAR NOCTURNAL JETTING NOSING INTO SOUTHWESTERN NORTH CAROLINA ALONG THE FRONT LATE FRIDAY INTO FRIDAY NIGHT... WHICH COULD INDUCE ENOUGH FORCING AND LOW LEVEL MOISTURE POOLING TO KICK OFF SLOW MOVING SHOWERS OR STORMS. THE GFS/ECMWF BOTH SUGGEST THAT THIS MOISTURE IS ROOTED IN THE REMAINS OF NOW TROPICAL STORM HERMINE... QUITE REASONABLE CONSIDERING THE MEAN FLOW PATTERN AND GOOD MODEL AGREEMENT. WILL SPREAD IN CHANCE POPS FROM SOUTHWEST TO EAST VERY LATE FRIDAY THROUGH FRIDAY NIGHT INTO SATURDAY MORNING. THE GFS/ECMWF ALSO BOTH SHOW A LOW FORMING AND TRACKING ALONG THE FRONT JUST TO OUR SOUTH... WHICH RESULTS IN AN ENHANCED NORTHEAST LOW LEVEL FLOW FRIDAY NIGHT INTO SATURDAY...POTENTIALLY RESULTING IN A WEAK IN SITU DAMMING EVENT. WHILE IT IS TOO FAR OFF WITH TOO MUCH UNCERTAINTY TO PUT MUCH FAITH IN SUCH A SCENARIO... IT WILL BE SOMETHING TO WATCH IN THE COMING DAYS. FOR NOW WILL TAPER POPS DOWN SATURDAY AFTERNOON BUT KEEP A GOOD BIT OF CLOUD COVER OVER THE AREA. WILL HAVE HIGHS NEAR NORMAL... 82 TO 88... BUT CONFIDENCE IS BELOW NORMAL AND IF THE PRECIPITATION COVERAGE IS GREATER THAN EXPECTED FRIDAY NIGHT AND SATURDAY...HIGHS COULD BE BELOW NORMAL ON SATURDAY. LOWS IN THE 60S. FOR SATURDAY NIGHT THROUGH MONDAY: THE BLOCKING VORTEX OVER NOVA SCOTIA FINALLY WEAKENS AND GETS NUDGED EASTWARD BY A STRONG SHORT WAVE NOW APPROACHING THE PACIFIC NORTHWEST. THE MID LEVEL RIDGE BETWEEN THESE TWO FEATURES DEAMPLIFIES SO IT LOOKS LIKELY THAT BROAD TROUGHING WILL BECOME REESTABLISHED OVER THE EASTERN UNITED STATES BY MONDAY. THE OPERATIONAL MODELS DIVERGE HOWEVER WITH THE ECMWF MUCH MORE AMPLIFIED THAN THE GFS... RESULTING IN THE ECMWF LEANING TOWARD KEEPING THE SURFACE FRONTAL ZONE JUST SOUTH OF THE CWA WITH COOLER TEMPERATURES AND DRY WEATHER... WHILE THE GFS ALLOWS THE WARM SECTOR TO SURGE UP INTO THE CAROLINAS WITH MUCH WARMER TEMPERATURES AND BETTER RAIN CHANCES. THE LESS AMPLIFIED GFS HAS SUPPORT FROM THE ECMWF ENSEMBLE MEAN AND THUS WAS PREFERRED. WILL HAVE LOW CHANCES OF AFTERNOON THROUGH EVENING SHOWERS OR THUNDERSTORMS... WITH TEMPERATURES GENERALLY A CATEGORY ABOVE NORMAL. -GIH && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 145 AM TUESDAY... VFR CONDITIONS WILL CONTINUE TO BE THE RULE DURING THE 06Z VALID TAF PERIOD. THE LATEST GUIDANCE HAS BACKED OFF SOMEWHAT WITH THE POTENTIAL FOR FOG AND/OR STRATUS...WITH MODEL SOUNDINGS SOMEWHAT DRY IN THE BOUNDARY LAYER...MOS GUIDANCE HIGHER WITH VISIBILITIES AND CEILINGS AROUND 12Z ESPECIALLY AT KFAY AND KRWI...AND SREF ENSEMBLE GUIDANCE WITH RELATIVELY LOW CHANCES FOR IFR CONDITIONS. HAVE FORECAST CATEGORICAL OR TEMPO MVFR FOG AROUND SUNRISE AT KRDU...KFAY AND KRWI...WITH TEMPO IFR AT THE LATTER TWO...WITH CONFIDENCE OF LIFR CONDITIONS AT PRESENT NOT HIGH. MAY BE A LITTLE BETTER POTENTIAL FOR STRATUS LATE TONIGHT...JUST BEYOND THE 06Z VALID TAF PERIOD...WITH SLIGHTLY STRONGER 925MB WINDS ALOFT AND A LOWER INVERSION HEIGHT WITH MOISTURE INCREASING SLIGHTLY. POTENTIAL FOR FOG LIKELY A LITTLE GREATER AT KRWI WHERE SURFACE WINDS WILL BE LIGHTER LATE TONIGHT...BUT A COMBINATION OF A LIGHT WIND AND CIRRUS MOVING INTO CENTRAL NORTH CAROLINA SHOULD LIMIT FOG POTENTIAL AT OTHER TAF SITES. VFR CONDITIONS ARE ANTICIPATED OVERALL BEYOND THE 06Z VALID TAF PERIOD. A COLD FRONT MOVES THROUGH CENTRAL NORTH CAROLINA OVERNIGHT WEDNESDAY VEERING SURFACE WINDS. BASED ON A COMBINATION OF THE LATEST NAM AND GFS BUFR SOUNDINGS...THE NEXT BEST CHANCE OF IFR CONDITIONS FOR THE END OF THE WEEK AND THE START OF THE WEEKEND COMES LATE SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...CBL SHORT TERM...CBL LONG TERM...HARTFIELD AVIATION...DJF 000 FXUS62 KILM 070637 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 237 AM EDT TUE SEP 7 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE MIDDLE OF THIS WEEK. A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN CHANCES. A WARM FRONT MAY BRING SOME BETTER RAIN CHANCES OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 9 PM MONDAY...HIGH PRESSURE CENTERED OFF THE NORTHEAST U.S. COAST IS RIDGING SOUTHWARD TO THE NC OUTER BANKS. EASTERLY FLOW IS ADVECTING A WARM AND SEASONABLY HUMID AIRMASS ONSHORE. WITH GENERALLY CLEAR SKIES AND RIDGING AT THE SURFACE AND ALOFT THE BOUNDARY LAYER SHOULD DECOUPLE WITH AREAS OF FOG DEVELOPING AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW AT LEAST 1500 FT OF SIGNIFICANT MOISTURE BEFORE ANY DRYING OCCURS ALOFT...ANOTHER FACTOR THAT FAVORS FOG FORMATION. AN OLD OUTFLOW BOUNDARY LEFT OVER FROM EARLY AFTERNOON SHOWER ACTIVITY OFFSHORE...EXTENDS FROM MYRTLE BEACH OFFSHORE TO NEAR THE FRYING PAN SHOALS TOWER. RADAR HAS SHOWN SPOTTY ECHOES ALONG THIS BOUNDARY FOR THE PAST HOUR...AND AN ISOLATED SHOWER COULD DEVELOP AT ANY TIME HERE FOR THE NEXT FEW HOURS. RIDGING ALOFT WILL BUILD A SUBSIDENCE INVERSION BETWEEN 650 AND 700 MB WHICH SHOULD PRECLUDE DEEPER CONVECTION AND THUNDER CHANCES. THE ATMOSPHERE IS VERY SIMILAR THERMALLY TO LAST NIGHT AND WE ARE EXPECTING LOWS SIMILAR TO THAT OBSERVED LAST NIGHT: LOW TO MID 60S INLAND WITH A NARROW ZONE OF UPPER 60S AND LOWER 70S ALONG THE IMMEDIATE COAST WITH THE LIGHT ONSHORE FLOW. THE NORMAL COLD SPOTS ON HIGHLY RADIATIVE SOIL TYPES ACROSS SOUTHEAST NC SHOULD FALL INTO THE 50S AGAIN TONIGHT. && .SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...A WARM TUESDAY ON TAP AS UPPER LEVEL RIDGE FLATTENS BUT HOLDS ON ACROSS THE CAROLINAS. HIGH PRESSURE AT THE SFC LOCATED OFF OF CAPE HATTERAS AND A TROUGH DEVELOPING EAST OF JACKSONVILLE, FL. SKY COVER FAIRLY MINIMAL THANKS TO THE SINKING AIR SUPPLIED BY THE RIDGE ALOFT BUT THE SURFACE TROUGH TO THE SOUTH MAY DRAW IN ENOUGH MOISTURE OVER SRN ZONES TO WARRANT A PARTLY CLOUDY FORECAST. THE UPPER RIDGE FLATTENS AND WEAKENS SUFFICIENTLY ON WEDNESDAY TO ALLOW A COLD FRONT TO APPROACH FROM THE NW. THIS BOUNDARY WILL SLOWLY CROSS THE FORECAST AREA WEDNESDAY NIGHT. WITH A DIURNALLY UNFAVORABLE TIME FOR INSTABILITY AND WEAK FORCING PRECIPITATION WILL BE HARD PRESSED TO DEVELOP. SLIGHT CHANCE POPS ALONG THE COAST FOR SHOWERS AND LOW END CHANCE POPS FOR DEEPER CONVECTION OVER WATER WHERE HEAT AND MOISTURE SOURCES ARE BETTER. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 PM MONDAY...COLD FRONT IN THE AREA THU MORNING WILL CONTINUE SLOWLY MOVING SOUTH INTO FRI AS 5H RIDGE CONTINUES TO BREAK DOWN. REMAINS OF FRONT STALLS JUST SOUTH OF THE AREA FRI AND LINGERS THERE THROUGH SAT. AT THE SAME TIME MOISTURE AND DYNAMICS FROM THE REMAINS OF TS HERMINE ROUND THE TOP OF THE WEAKENING RIDGE AND PASS OVER THE AREA. PRECIPITABLE WATER VALUES RISE ABOVE 2 INCHES FRI NIGHT INTO SAT AND SOUNDINGS SUGGEST SOME ELEVATED CONVECTION COULD DEVELOP FRI NIGHT. TIMING OF HERMINE REMAINS WILL PLAY A LARGE ROLE IN STORM COVERAGE SAT. LATEST GFS/ECMWF TIMING WOULD HAVE BEST DYNAMICS ARRIVING COINCIDENT WITH MAX HEATING ON SAT WHICH COULD LEAD TO GREATER STORM COVERAGE. STALLED FRONT LIFTS NORTH AS A WARM FRONT SAT NIGHT INTO SUN. PWATS REMAIN ABOVE 2 INCHES THROUGH THE END OF THE PERIOD AND DIURNAL HEATING COULD PRODUCE AFTERNOON SHOWERS AND T-STORMS ON SUN AND MON. GFS HINTING AT A SHORTWAVE OR TWO IN NEARLY ZONAL FLO AT THE END OF THE PERIOD BUT CONFIDENCE IN THESE FEATURES IS LIMITED. KEEPING TEMPERATURES ABOVE CLIMO...THOUGH NOT AS WARM AS FORECAST YESTERDAY. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 06Z...MODERATE CONFIDENCE FORECAST THROUGH THE VALID PERIOD DUE TO POTENTIAL FOG AND/OR STRATUS OVERNIGHT. CLOUD COVER HAS MOSTLY ERODED OVER THE AREA...WITH THE EXCEPTION BEING AT THE MYRTLES WHERE SOME STRATOCU FOCUSED ALONG AN OLD OUTFLOW BOUNDARY CONTINUES TO DEVELOP AND MOVE ONSHORE. WINDS STAYED ELEVATED LONGER THAN PREVIOUSLY ANTICIPATED...SO HAVE SLOWED ONSET OF FOG OVERNIGHT. AT THE SAME TIME...THE LONGER DURATION SE FLOW HAS ADVECTED EVEN MORE MOISTURE INTO THE SURFACE LAYER...SO ONCE WINDS DO GO CALM FOG LOOKS LIKE A GOOD BET...ESPECIALLY INLAND. FOR THIS REASON HAVE PREDOMINATE IFR FOG AT BOTH INLAND TERMINALS TOWARDS TUESDAY MORNING. THE LONGER DURATION WINDS HAVE INHIBITED EARLIER RADIATIONAL COOLING...SO LIFR NOT ANTICIPATED...BUT SIGNIFICANT RESTRICTIONS APPEAR LIKELY FOR AT LEAST A SHORT TIME TOWARDS SUNRISE. AT THE COAST...CONFIDENCE IS LOWER IN FOG DUE TO CONTINUED STRATOCU AND THE WINDS PREVIOUSLY MENTIONED. BUFR PROFILES INDICATING THE DEVELOPMENT OF A WEAK...BUT STILL PRESENT...LLJ JUST ABOVE THE B/L. THIS MAY PRODUCE MORE OF A STRATUS ISSUE...AND BUFR PROFILES ARE INDICATING MORE STRATUS THAN FOG AT THE COAST. HAVE CHOSEN TO USE TEMPO BKN MVFR CIGS AT THE MYRTLES WHERE TD/S ARE IN THE 70S...COMBINED WITH MVFR VSBYS. WOULD NOT BE SURPRISED IF VSBYS STAY UNRESTRICTED HOWEVER...AND MAY NEED TO ISSUE SOME AMENDMENTS OVERNIGHT. HAVE MVFR FOG AT ILM WITH SCT AT MVFR LEVELS TO CONTINUE TO REFLECT POTENTIAL STRATUS THERE. AFTER SUNRISE TUESDAY FOG WILL BURN OFF AND SOME EARLY MORNING STRATOCU WILL LIKELY DEVELOP. AS RIDGE ALOFT FINALLY BUILDS OVERHEAD...SUBSIDENCE CAP WILL HELP ERODE/INHIBIT MUCH CLOUD DEVELOPMENT DURING THE AFTN...AND ANTICIPATE NEARLY CLOUDLESS SKY CONDITIONS NEAR THE COAST. INLAND MAY SEE SOME AFTN DIURNAL CU WITH SIGNIFICANT AFTN HEATING. WINDS THROUGH THE DAY WILL VEER NE TO SE...AND INCREASE TO AROUND 10 KTS. CLOUD COVER WILL AGAIN RAPIDLY ERODE WITH LOSS OF HEATING TUESDAY NIGHT. WINDS WILL DROP TO NEAR CALM AND SOME STRATOCU WILL AGAIN AFFECT THE COAST BY THE END OF THIS VALID PERIOD. EXTENDED OUTLOOK...MORNING FOG POSSIBLE EACH MORNING. COLD FRONT WILL APPROACH THE AREA THURSDAY WITH A SLIGHT CHANCE OF SHOWERS. MORE SHOWERS ARE POSSIBLE SATURDAY WITH THE ADVANCE OF A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM MONDAY...A NARROW RIDGE OF HIGH PRESSURE EXTENDS FROM JUST OFF THE NEW ENGLAND COASTLINE DOWN TO THE OUTER BANKS. EASTERLY FLOW THIS AFTERNOON WAS ENHANCED BY THE SEABREEZE WITH LOTS OF 15 KNOT REPORTS OBSERVED UP AND DOWN THE CAROLINA COAST. WITH THE DECAY OF THE SEABREEZE CIRCULATION WE EXPECT TO SEE WINDS FALL BACK TOWARD 10 KT OVERNIGHT WITH DIRECTIONS BACKING TO THE NORTHEAST. SATELLITE AND RADAR IMAGERY SUGGESTS THERE IS A NARROW CONVERGENT WIND AXIS EXTENDING FROM NEAR MYRTLE BEACH OUT TO THE FRYING PAN SHOALS TOWER. THIS IS LIKELY AN OUTFLOW BOUNDARY FROM SHOWERS BACK DURING THE EARLY AFTERNOON HOURS. ISOLATED SHOWERS MAY REDEVELOP ALONG THIS BOUNDARY OVER THE NEXT 3-6 HOURS. SEAS ARE 2-3 FT THIS EVENING...MAINLY IN A 5-6 SECOND EASTERLY WIND WAVE. SEAS JUST A COUPLE HOURS AGO HAD REACHED 4 FT NORTH OF CAPE FEAR DURING THE STRONGEST PORTION OF THE SEABREEZE FLOW. SEAS SHOULD FALL TO AROUND 2 FT OVERNIGHT. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...AS OFFSHORE HIGH WEAKENS AND PULLS EASTWARD SLIGHTLY WINDS WILL TURN TO THE EAST AS THEY REMAIN CAPPED AT 10 KT. A SFC TROUGH DEVELOPING EAST OF NRN FLORIDA WILL ALSO AID IN THIS VEER IN DIRECTION FROM NE TO E. WITH SUCH LIGHT WINDS AND THE ABSENCE OF ANY SIGNIFICANT GROUND SWELL SEAS WILL AVERAGE 2 FT OR LESS. AN APPROACHING COLD FRONT WILL TURN FLOW TO SOUTHWESTERLY ON WEDNESDAY BUT NO REAL INCREASE IN GRADIENT EXPECTED UNTIL LATE IN THE DAY OR AT NIGHT AT WHICH TIME ABOUT A 5 KT INCREASE EXPECTED IN ADDITION TO SOME GUSTINESS. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...GENERAL NORTHERLY FLOW IN THE POST FRONT REGIME BUT PRESSURE GRADIENT IS LIGHT ENOUGH THAT ANY MESOSCALE BOUNDARIES WILL OVERRIDE THE NORTHERLY WIND COMPONENT. SPEEDS WILL GENERALLY BE 10 KT OR LESS AND SEAS WILL RUN 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ AVIATION...JDW 000 FXUS62 KRAH 070546 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 145 AM EDT TUE SEP 7 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TODAY. A WEAK COLD FRONT CROSSES THE AREA LATE WEDNESDAY. BEHIND THE FRONT...HIGH PRESSURE GRADUALLY BUILDS SOUTH INTO THE AREA DURING THE REST OF THE WORK WEEK. && .NEAR TERM /THROUGH TUESDAY NIGHT/... AS OF 920 PM MONDAY... TONIGHT: ONLY COSMETIC CHANGES REQUIRED TO PREVIOUS FORECAST. MID LEVEL H5 RIDGING CENTERED OVER NORTHERN AL HAS STRENGTHENED SOME 30 METERS PER 00Z RAOBS... AND WILL CONTINUE TO BUILD EASTWARD OVERNIGHT IN THE WAKE OF A DEPARTING L/W TROUGH AXIS SITUATED JUST OFFSHORE THE EAST COAST. MEANWHILE AT THE SURFACE... A 1023 MB RIDGE JUST OFFSHORE THE TIDEWATER OF VA SHOULD CONTINUE TO REMAIN WELL ENTRENCHED ACROSS THE CAROLINAS OWING TO THE SUBSIDENCE DOWNSTREAM OF THE MID LEVEL RIDGING. GENERALLY EASTERLY FLOW AROUND THE SURFACE RIDGE FOR THE PAST 12-18 HOURS HAS RESULTED IN A MODEST RECOVERY IN LOW LEVEL MOISTURE ACROSS CENTRAL NC DURING THAT TIME... WITH DEWPOINTS RANGING AT 9 PM FROM MAINLY UPPER 50S NORTHWEST TO MIDDLE 60S SOUTH. OVERNIGHT LOWS SHOULD NOT BE TOO FAR OFF OF THOSE OBSERVED DEWPOINT TEMPERATURES... WITH MOST LOCALES EXPECTED TO DIP TO WITHIN A FEW DEGREES OF 60. THE INCREASED LOW LEVEL MOISTURE IN CONJUNCTION WITH LIGHT-CALM WINDS WITHIN THE SURFACE RIDGE AXIS... AND AN INITIALLY MOSTLY CLEAR SKY (ASIDE FROM MAINLY SCT STRATOCUMULUS TRAPPED AT THE BASE OF A SUBSIDENCE ATTENDING THE INCOMING RIDGE ALOFT)... MAY PROMOTE THE DEVELOPMENT OF PATCHES OF STRATUS AND FOG BY DAYBREAK... PARTICULARLY IN THE HIGHER DEWPOINT AIR OVER THE SOUTHERN AND SOUTHWESTERN ZONES. THIS TREND WAS ALREADY REFLECTED IN THE GRIDDED FORECAST. TUESDAY AND TUESDAY NIGHT: THE AFOREMENTIONED NORTHERN PLAINS SHORTWAVE AND ITS ASSOCIATED SURFACE LOW WILL DRIVE A COLD FRONT SOUTHEAST INTO THE OHIO VALLEY REGION ON TUESDAY. THE AIR MASS SHOULD MODERATE A BUT MORE WITH A DEVELOPING SOUTHWESTERLY FLOW AND 1000 TO 850 MILLIBAR THICKNESSES FORECAST TO RISE INTO THE 1420 TO 1425 METER RANGE. THICKNESS AND 850 MILLIBAR MIXING BOTH YIELD VALUES CONSISTENT WITH STATISTICAL GUIDANCE...88 TO 92. CONTINUED WITH DRY FORECAST AS PW RECOVERY IS FORECAST TO BE RATHER WEAK DURING THE DAY TUESDAY AND MODELS ARE NOT SHOWING MUCH DEVELOPMENT OF A PREFRONTAL TROUGH WITH HIGH PRESSURE REMAINING DOMINANT. SHOULD SEE MAINLY CLEAR SKIES TUESDAY NIGHT WITH SOUTHWESTERLY FLOW AHEAD OF WHAT LOOKS TO BE A MAINLY DRY APPROACHING COLD FRONT. HAVE LOWS WARMER THAN GUIDANCE...65 TO 67. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 235 PM MONDAY... FOR WEDNESDAY AND WEDNESDAY NIGHT: MID LEVEL VORTEX NOW PUSHING THROUGH THE DAKOTAS DEEPENS WHILE CROSSING THE UPPER GREAT LAKES TOWARD FAR SOUTHERN QUEBEC BY DAWN THURSDAY. A CORRESPONDING SURFACE FRONT PUSHES TO THE SOUTHERN APPALACHIANS BY WEDNESDAY AFTERNOON THEN DROPS SOUTHEAST THROUGH NORTH CAROLINA WEDNESDAY NIGHT... BUT WITH INCIPIENT DRY AIR (PRECIPITABLE WATER WELL UNDER ONE INCH) AND A WESTERLY DOWNSLOPE FLOW AT 850 MILLIBAR PRECEDING THE FRONT... PRECIPITATION CHANCES APPEAR LOW. WE WILL SEE PRECIPITABLE WATER VALUES INCREASE BRIEFLY TO NEAR 1.5 INCHES JUST AHEAD OF THE FRONT... AND THE NAM/GFS DO SHOW A WEAK WAVE DROPPING SOUTHEAST THROUGH THE STATE WITH THETA-E RIDGING NOSING IN AT 850 MILLIBAR. HOWEVER NO FORCING FOR ASCENT IS EVIDENT ELSEWHERE THROUGH THE TROPOSPHERE... INCLUDING AT JET LEVEL... AND THE PRECIPITATION AMOUNTS GENERATED BY THE MODELS ARE SLIM TO NONE. INSTABILITY IS ALSO LIMITED WITH THE GFS SHOWING SBCAPE PEAKING AT 500 J/KG RIGHT ALONG THE FRONT... WITH A DRY SUBCLOUD LAYER. WILL KEEP THE FORECAST DRY BUT INCLUDE A PERIOD OF ISOLATED SPRINKLES LATE AFTERNOON INTO MID EVENING AS LAPSE RATES ALOFT STEEPEN WITH BROAD MID LEVEL TROUGH PASSAGE. GIVEN THE DRY LOW LEVELS... A FEW ENHANCED GUSTS ARE POSSIBLE NEAR THESE SHOWERS. THICKNESSES CLIMB FURTHER WEDNESDAY TO AROUND 15 TO 20 METERS ABOVE NORMAL... AND WITH A DRY ADIABATIC LOW LEVEL PROFILE... HIGHS OF 89 TO 94 STILL LOOK FINE. GIVEN THE DELAY IN CLEARING OVERNIGHT ALONG WITH THE WEAK ADVECTION OF LOWER THICKNESSES AND STILL MILD AIR AT 925 TO 850 MILLIBAR... WILL BUMP LOWS UP JUST A BIT MAINLY ACROSS THE NORTH TO 64 TO 70. FOR THURSDAY AND THURSDAY NIGHT: THE FRONT IS EXPECTED TO SETTLE ALONG THE SOUTHERN BORDER OF NORTH CAROLINA THURSDAY. AN ELONGATED CANADIAN SOURCE HIGH ATTEMPTS TO BUILD IN BEHIND THE FRONT FROM THE NORTHWEST... HOWEVER THE COOLER AIR APPEARS TO BE HINDERED BY THE MOUNTAINS SUCH THAT LOW LEVEL THICKNESSES HOLD ABOVE NORMAL... AND A WEAK LEE TROUGH DEVELOPS OVER THE PIEDMONT IN THE AFTERNOON. THE COLUMN DRIES BACK OUT RATHER QUICKLY WITH NO INSTABILITY NOR LARGE SCALE LIFT... SO DO NOT ANTICIPATE ANY PRECIPITATION ALONG THE FRONTAL ZONE OR TROUGH ON THURSDAY... ALTHOUGH WE COULD SEE SOME MID OR HIGH LEVEL CLOUDINESS IN THE MORNING AS ANOTHER WEAK WAVE ALOFT DROPS THROUGH NORTH CAROLINA. HIGHS 87 TO 93. LOWS 58 TO 65 WITH A SECONDARY SURGE OF DRIER AIR DROPPING THROUGH THE STATE OVERNIGHT. -GIH && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 235 PM MONDAY... FOR FRIDAY THROUGH SATURDAY: THE FRONT TO OUR SSW TRIES TO HEAD BACK NORTHEAST AS A WARM FRONT ON FRIDAY ACCORDING TO THE LATEST GFS/ECMWF. BUT AS THE MID LEVEL VORTEX SITS AND SPINS OVER NOVA SCOTIA WITH TROUGHING ENCOMPASSING MOST OF THE EASTERN SEABOARD AND WESTERN ATLANTIC... THE BLOCKING PATTERN SHOULD HELP KEEP THE SURFACE RIDGE DOMINANT THROUGH FRIDAY NIGHT. BUT THE ECMWF (AND TO A LESSER DEGREE THE GFS) INDICATES 850 MILLIBAR NOCTURNAL JETTING NOSING INTO SOUTHWESTERN NORTH CAROLINA ALONG THE FRONT LATE FRIDAY INTO FRIDAY NIGHT... WHICH COULD INDUCE ENOUGH FORCING AND LOW LEVEL MOISTURE POOLING TO KICK OFF SLOW MOVING SHOWERS OR STORMS. THE GFS/ECMWF BOTH SUGGEST THAT THIS MOISTURE IS ROOTED IN THE REMAINS OF NOW TROPICAL STORM HERMINE... QUITE REASONABLE CONSIDERING THE MEAN FLOW PATTERN AND GOOD MODEL AGREEMENT. WILL SPREAD IN CHANCE POPS FROM SOUTHWEST TO EAST VERY LATE FRIDAY THROUGH FRIDAY NIGHT INTO SATURDAY MORNING. THE GFS/ECMWF ALSO BOTH SHOW A LOW FORMING AND TRACKING ALONG THE FRONT JUST TO OUR SOUTH... WHICH RESULTS IN AN ENHANCED NORTHEAST LOW LEVEL FLOW FRIDAY NIGHT INTO SATURDAY...POTENTIALLY RESULTING IN A WEAK IN SITU DAMMING EVENT. WHILE IT IS TOO FAR OFF WITH TOO MUCH UNCERTAINTY TO PUT MUCH FAITH IN SUCH A SCENARIO... IT WILL BE SOMETHING TO WATCH IN THE COMING DAYS. FOR NOW WILL TAPER POPS DOWN SATURDAY AFTERNOON BUT KEEP A GOOD BIT OF CLOUD COVER OVER THE AREA. WILL HAVE HIGHS NEAR NORMAL... 82 TO 88... BUT CONFIDENCE IS BELOW NORMAL AND IF THE PRECIPITATION COVERAGE IS GREATER THAN EXPECTED FRIDAY NIGHT AND SATURDAY...HIGHS COULD BE BELOW NORMAL ON SATURDAY. LOWS IN THE 60S. FOR SATURDAY NIGHT THROUGH MONDAY: THE BLOCKING VORTEX OVER NOVA SCOTIA FINALLY WEAKENS AND GETS NUDGED EASTWARD BY A STRONG SHORT WAVE NOW APPROACHING THE PACIFIC NORTHWEST. THE MID LEVEL RIDGE BETWEEN THESE TWO FEATURES DEAMPLIFIES SO IT LOOKS LIKELY THAT BROAD TROUGHING WILL BECOME REESTABLISHED OVER THE EASTERN UNITED STATES BY MONDAY. THE OPERATIONAL MODELS DIVERGE HOWEVER WITH THE ECMWF MUCH MORE AMPLIFIED THAN THE GFS... RESULTING IN THE ECMWF LEANING TOWARD KEEPING THE SURFACE FRONTAL ZONE JUST SOUTH OF THE CWA WITH COOLER TEMPERATURES AND DRY WEATHER... WHILE THE GFS ALLOWS THE WARM SECTOR TO SURGE UP INTO THE CAROLINAS WITH MUCH WARMER TEMPERATURES AND BETTER RAIN CHANCES. THE LESS AMPLIFIED GFS HAS SUPPORT FROM THE ECMWF ENSEMBLE MEAN AND THUS WAS PREFERRED. WILL HAVE LOW CHANCES OF AFTERNOON THROUGH EVENING SHOWERS OR THUNDERSTORMS... WITH TEMPERATURES GENERALLY A CATEGORY ABOVE NORMAL. -GIH && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... AS OF 145 AM TUESDAY... VFR CONDITIONS WILL CONTINUE TO BE THE RULE DURING THE 06Z VALID TAF PERIOD. THE LATEST GUIDANCE HAS BACKED OFF SOMEWHAT WITH THE POTENTIAL FOR FOG AND/OR STRATUS...WITH MODEL SOUNDINGS SOMEWHAT DRY IN THE BOUNDARY LAYER...MOS GUIDANCE HIGHER WITH VISIBILITIES AND CEILINGS AROUND 12Z ESPECIALLY AT KFAY AND KRWI...AND SREF ENSEMBLE GUIDANCE WITH RELATIVELY LOW CHANCES FOR IFR CONDITIONS. HAVE FORECAST CATEGORICAL OR TEMPO MVFR FOG AROUND SUNRISE AT KRDU...KFAY AND KRWI...WITH TEMPO IFR AT THE LATTER TWO...WITH CONFIDENCE OF LIFR CONDITIONS AT PRESENT NOT HIGH. MAY BE A LITTLE BETTER POTENTIAL FOR STRATUS LATE TONIGHT...JUST BEYOND THE 06Z VALID TAF PERIOD...WITH SLIGHTLY STRONGER 925MB WINDS ALOFT AND A LOWER INVERSION HEIGHT WITH MOISTURE INCREASING SLIGHTLY. POTENTIAL FOR FOG LIKELY A LITTLE GREATER AT KRWI WHERE SURFACE WINDS WILL BE LIGHTER LATE TONIGHT...BUT A COMBINATION OF A LIGHT WIND AND CIRRUS MOVING INTO CENTRAL NORTH CAROLINA SHOULD LIMIT FOG POTENTIAL AT OTHER TAF SITES. VFR CONDITIONS ARE ANTICIPATED OVERALL BEYOND THE 06Z VALID TAF PERIOD. A COLD FRONT MOVES THROUGH CENTRAL NORTH CAROLINA OVERNIGHT WEDNESDAY VEERING SURFACE WINDS. BASED ON A COMBINATION OF THE LATEST NAM AND GFS BUFR SOUNDINGS...THE NEXT BEST CHANCE OF IFR CONDITIONS FOR THE END OF THE WEEK AND THE START OF THE WEEKEND COMES LATE SATURDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...DJF NEAR TERM...MWS/SMITH SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...DJF 000 FXUS62 KMHX 070142 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 935 PM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE TO THE NORTHEAST WILL CONTINUE TO EXTEND SOUTHWEST INTO THE REGION THROUGH TUESDAY NIGHT. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY AND SLIDE OFFSHORE SATURDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST SUNDAY AND MOVE INTO THE AREA MONDAY. && .NEAR TERM /THROUGH TONIGHT/... MINOR UPDATE TO ADJUST SKY CONDITION TO CLEAR OVERNIGHT. EARLIER CLOUDS ALONG COAST HAVE MOVED OFFSHORE WITH SHRT WV AND CLEAR EXPECTED OVERNIGHT. GOOD RADIATIONAL COOLING CONDITIONS WILL ALLOW TEMPS TO DROP INTO 60S INLAND AND AROUND 70 COAST. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 2 PM MON...CONT DRY TUE AND WED AS SFC HIGHS CONTS TO EXTEND SW INTO THE AREA WITH RDG ALOFT JUST TO THE S. HIGHS TUE WILL REACH UPR 80S INLAND WITH AROUND 90 WED AS FLOW GOES SW AHEAD OF APPROACHING COLD FRONT. FRONT WILL DROP SE THROUGH THE AREA WED NIGHT. GFS CONT TO BE WETTEST MODEL WITH SOME QPF MAINLY CST. NAM AND ECMWF ARE DRIER...FOR NOW ADDED SLIGHT POP CNTRL AND SRN CSTL WTRS FOR THE FROPA LATER WED NIGHT. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 2 PM MON...COLD FRONT WILL STALL TO THE S THU WITH HIGH PRES TO THE N. EXPECT DRY WX THU AND FRI WITH TEMPS MAINLY MID/UPR 80S. GFS SHOWS REMNANTS OF HERMINE MAKING IT TO OH VLY REGION LATE FRI BEFORE MERGING WITH DEVELOPING ERN TRF AND CROSSING THE REGION SAT. ECMWF IS MORE ROBUST WITH THE REMNANTS SHOWING A WELL DEFINED VORT MAX AND ASSOC PRECIP BULLS EYE MOVING ACROSS SAT. WILL LEAN MORE TOWARD GFS BUT DO EXPECT BETTER MOISTURE WILL LEAD TO SCT CONVECTION SAT. SRT WAVES CROSSING IN ZONAL FLOW WILL LEAD TO CONT CHC POPS SUN INTO MON AS COLD FRONT SAGS S INTO THE AREA. HIGHS MAINLY MID TO UPR 80S INLAND WITH LOW TO MID 80S CST THRU THE PERIOD. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 00Z TUE...HIGH PRESSURE CURRENTLY IN CONTROL OVER MUCH OF THE MID- ATLANTIC REGION WILL GIVE WAY TO MAINLY CLEAR SKIES THROUGHOUT THE TAF PERIOD. WITH LIGHT WINDS AND CLEAR SKIES OVERNIGHT...ANTICIPATE SOME PATCHY FOG TO DEVELOP BETWEEN 06-12Z TUESDAY. ANY LOW LEVEL MOISTURE IN PLACE EARLY TUESDAY WILL QUICKLY DISSIPATE AFTER SUNRISE AS BOUNDARY LAYER MIXING INCREASES. SIMILAR TO TODAY...EXPECT CLEAR SKIES AND WINDS VEERING NE TO SE AROUND 5-8KTS TUESDAY. BEYOND 18Z TUESDAY...A FRONT WILL APPROACH THE REGION WEDNESDAY INTO THURSDAY. CLOUD COVER AND SW WINDS WILL BE ON THE INCREASE WEDNESDAY AFTERNOON AHEAD OF THE BOUNDARY. THE BEST CHANCE OF ANY PRECIPITATION WILL BE WEDNESDAY NIGHT INTO EARLY THURSDAY. HIGH PRESSURE WILL BUILD INTO THE REGION LATE THURSDAY BEFORE THE NEXT SYSTEM APPROACHES THIS WEEKEND. && .MARINE... AS OF 745 PM MON...DECREASED WIND SPEEDS OVER THE SOUNDS AND WATERS NORTH OF OREGON INLET TO BETTER MATCH CURRENT OBSERVATIONS. NO OTHER CHANGES MADE. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RF NEAR TERM...JBM SHORT TERM...RF LONG TERM...RF AVIATION...LP/BM MARINE...HSA 000 FXUS62 KILM 070126 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 926 PM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE MIDDLE OF THIS WEEK. A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN CHANCES. A WARM FRONT MAY BRING SOME BETTER RAIN CHANCES OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM MONDAY...HIGH PRESSURE CENTERED OFF THE NORTHEAST U.S. COAST IS RIDGING SOUTHWARD TO THE NC OUTER BANKS. EASTERLY FLOW IS ADVECTING A WARM AND SEASONABLY HUMID AIRMASS ONSHORE. WITH GENERALLY CLEAR SKIES AND RIDGING AT THE SURFACE AND ALOFT THE BOUNDARY LAYER SHOULD DECOUPLE WITH AREAS OF FOG DEVELOPING AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW AT LEAST 1500 FT OF SIGNIFICANT MOISTURE BEFORE ANY DRYING OCCURS ALOFT...ANOTHER FACTOR THAT FAVORS FOG FORMATION. AN OLD OUTFLOW BOUNDARY LEFT OVER FROM EARLY AFTERNOON SHOWER ACTIVITY OFFSHORE...EXTENDS FROM MYRTLE BEACH OFFSHORE TO NEAR THE FRYING PAN SHOALS TOWER. RADAR HAS SHOWN SPOTTY ECHOES ALONG THIS BOUNDARY FOR THE PAST HOUR...AND AN ISOLATED SHOWER COULD DEVELOP AT ANY TIME HERE FOR THE NEXT FEW HOURS. RIDGING ALOFT WILL BUILD A SUBSIDENCE INVERSION BETWEEN 650 AND 700 MB WHICH SHOULD PRECLUDE DEEPER CONVECTION AND THUNDER CHANCES. THE ATMOSPHERE IS VERY SIMILAR THERMALLY TO LAST NIGHT AND WE ARE EXPECTING LOWS SIMILAR TO THAT OBSERVED LAST NIGHT: LOW TO MID 60S INLAND WITH A NARROW ZONE OF UPPER 60S AND LOWER 70S ALONG THE IMMEDIATE COAST WITH THE LIGHT ONSHORE FLOW. THE NORMAL COLD SPOTS ON HIGHLY RADIATIVE SOIL TYPES ACROSS SOUTHEAST NC SHOULD FALL INTO THE 50S AGAIN TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...A WARM TUESDAY ON TAP AS UPPER LEVEL RIDGE FLATTENS BUT HOLDS ON ACROSS THE CAROLINAS. HIGH PRESSURE AT THE SFC LOCATED OFF OF CAPE HATTERAS AND A TROUGH DEVELOPING EAST OF JACKSONVILLE, FL. SKY COVER FAIRLY MINIMAL THANKS TO THE SINKING AIR SUPPLIED BY THE RIDGE ALOFT BUT THE SURFACE TROUGH TO THE SOUTH MAY DRAW IN ENOUGH MOISTURE OVER SRN ZONES TO WARRANT A PARTLY CLOUDY FORECAST. THE UPPER RIDGE FLATTENS AND WEAKENS SUFFICIENTLY ON WEDNESDAY TO ALLOW A COLD FRONT TO APPROACH FROM THE NW. THIS BOUNDARY WILL SLOWLY CROSS THE FORECAST AREA WEDNESDAY NIGHT. WITH A DIURNALLY UNFAVORABLE TIME FOR INSTABILITY AND WEAK FORCING PRECIPITATION WILL BE HARD PRESSED TO DEVELOP. SLIGHT CHANCE POPS ALONG THE COAST FOR SHOWERS AND LOW END CHANCE POPS FOR DEEPER CONVECTION OVER WATER WHERE HEAT AND MOISTURE SOURCES ARE BETTER. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 PM MONDAY...COLD FRONT IN THE AREA THU MORNING WILL CONTINUE SLOWLY MOVING SOUTH INTO FRI AS 5H RIDGE CONTINUES TO BREAK DOWN. REMAINS OF FRONT STALLS JUST SOUTH OF THE AREA FRI AND LINGERS THERE THROUGH SAT. AT THE SAME TIME MOISTURE AND DYNAMICS FROM THE REMAINS OF TS HERMINE ROUND THE TOP OF THE WEAKENING RIDGE AND PASS OVER THE AREA. PRECIPITABLE WATER VALUES RISE ABOVE 2 INCHES FRI NIGHT INTO SAT AND SOUNDINGS SUGGEST SOME ELEVATED CONVECTION COULD DEVELOP FRI NIGHT. TIMING OF HERMINE REMAINS WILL PLAY A LARGE ROLE IN STORM COVERAGE SAT. LATEST GFS/ECMWF TIMING WOULD HAVE BEST DYNAMICS ARRIVING COINCIDENT WITH MAX HEATING ON SAT WHICH COULD LEAD TO GREATER STORM COVERAGE. STALLED FRONT LIFTS NORTH AS A WARM FRONT SAT NIGHT INTO SUN. PWATS REMAIN ABOVE 2 INCHES THROUGH THE END OF THE PERIOD AND DIURNAL HEATING COULD PRODUCE AFTERNOON SHOWERS AND T-STORMS ON SUN AND MON. GFS HINTING AT A SHORTWAVE OR TWO IN NEARLY ZONAL FLO AT THE END OF THE PERIOD BUT CONFIDENCE IN THESE FEATURES IS LIMITED. KEEPING TEMPERATURES ABOVE CLIMO...THOUGH NOT AS WARM AS FORECAST YESTERDAY. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...MODERATE CONFIDENCE FORECAST THROUGH THE VALID PERIOD DUE TO POTENTIAL FOG AND/OR STRATUS OVERNIGHT. DIURNAL CU IS RAPIDLY DISSIPATING THIS EVE...AND SKC WILL BECOME THE SKY CONDITION IN THE NEXT FEW HOURS. SEA BREEZE HAS PENETRATED WELL INLAND...WHICH IS ACTING TO INCREASE SURFACE MOISTURE AS EVIDENCED BY RISING TD/S. ALTHOUGH WINDS WILL REMAIN ELEVATED AND GUSTY FOR THE NEXT FEW HOURS...THEY WILL GO TO NEAR CALM OVERNIGHT...WHICH WHEN COMBINED WITH CLEAR SKY CONDITIONS AND HIGH SURFACE MOISTURE PRESENTS AN OBVIOUS FOG/STRATUS THREAT OVERNIGHT. CONFIDENCE IS FAIRLY HIGH THAT AT LEAST MVFR FOG WILL DEVELOP INLAND...AND HAVE ALSO INTRODUCED TEMPO IFR TO LBT/FLO TOWARDS DAYBREAK TUESDAY. ALTHOUGH CROSSOVER TEMPERATURES (BASED ON DAYTIME MINIMUM OBSERVED DEWPOINTS) WILL PROBABLY NOT QUITE BE MET...MOISTURE ADVECTION THIS EVE WILL LIKELY RAISE TD/S ENOUGH THAT DEWPOINT DEPRESSIONS WILL BECOME MINIMIZED OVERNIGHT. AT THE COAST THE FORECAST IS A LITTLE TRICKIER SINCE BUFR PROFILES INDICATE THE DEVELOPMENT OF A WEAK...BUT STILL PRESENT...LLJ JUST ABOVE THE B/L. THIS MAY PRODUCE MORE OF A STRATUS ISSUE...AND BUFR PROFILES ARE INDICATING MORE STRATUS THAN FOG AT THE COAST. FOR NOW...HAVE MVFR VSBYS WITH SCT AT MVFR LEVELS AT THE COAST...WITH THE HIGHEST CHANCE OF STRATUS BEING AT THE MYRTLES WHERE TD/S ARE CURRENTLY IN THE LOW 70S. WILL WATCH DEVELOPMENT THIS EVE...AND UPDATE WITH 06Z ISSUANCE AS NECESSARY AND AS CONFIDENCE INCREASES. AFTER SUNRISE TUESDAY FOG WILL BURN OFF AND SOME EARLY MORNING STRATOCU WILL LIKELY DEVELOP. AS RIDGE ALOFT FINALLY BUILDS OVERHEAD...SUBSIDENCE CAP WILL HELP ERODE/INHIBIT MUCH CLOUD DEVELOPMENT DURING THE AFTN...AND ANTICIPATE NEARLY CLOUDLESS SKY CONDITIONS NEAR THE COAST. INLAND MAY SEE SOME AFTN DIURNAL CU WITH SIGNIFICANT AFTN HEATING. WINDS THROUGH THE DAY WILL VEER NE TO SE...AND INCREASE TO AROUND 10 KTS. EXTENDED OUTLOOK...MORNING FOG POSSIBLE EACH MORNING. COLD FRONT WILL APPROACH THE AREA THURSDAY WITH A SLIGHT CHANCE OF SHOWERS. MORE SHOWERS ARE POSSIBLE SATURDAY WITH THE ADVANCE OF A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM MONDAY...A NARROW RIDGE OF HIGH PRESSURE EXTENDS FROM JUST OFF THE NEW ENGLAND COASTLINE DOWN TO THE OUTER BANKS. EASTERLY FLOW THIS AFTERNOON WAS ENHANCED BY THE SEABREEZE WITH LOTS OF 15 KNOT REPORTS OBSERVED UP AND DOWN THE CAROLINA COAST. WITH THE DECAY OF THE SEABREEZE CIRCULATION WE EXPECT TO SEE WINDS FALL BACK TOWARD 10 KT OVERNIGHT WITH DIRECTIONS BACKING TO THE NORTHEAST. SATELLITE AND RADAR IMAGERY SUGGESTS THERE IS A NARROW CONVERGENT WIND AXIS EXTENDING FROM NEAR MYRTLE BEACH OUT TO THE FRYING PAN SHOALS TOWER. THIS IS LIKELY AN OUTFLOW BOUNDARY FROM SHOWERS BACK DURING THE EARLY AFTERNOON HOURS. ISOLATED SHOWERS MAY REDEVELOP ALONG THIS BOUNDARY OVER THE NEXT 3-6 HOURS. SEAS ARE 2-3 FT THIS EVENING...MAINLY IN A 5-6 SECOND EASTERLY WIND WAVE. SEAS JUST A COUPLE HOURS AGO HAD REACHED 4 FT NORTH OF CAPE FEAR DURING THE STRONGEST PORTION OF THE SEABREEZE FLOW. SEAS SHOULD FALL TO AROUND 2 FT OVERNIGHT. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...AS OFFSHORE HIGH WEAKENS AND PULLS EASTWARD SLIGHTLY WINDS WILL TURN TO THE EAST AS THEY REMAIN CAPPED AT 10 KT. A SFC TROUGH DEVELOPING EAST OF NRN FLORIDA WILL ALSO AID IN THIS VEER IN DIRECTION FROM NE TO E. WITH SUCH LIGHT WINDS AND THE ABSENCE OF ANY SIGNIFICANT GROUND SWELL SEAS WILL AVERAGE 2 FT OR LESS. AN APPROACHING COLD FRONT WILL TURN FLOW TO SOUTHWESTERLY ON WEDNESDAY BUT NO REAL INCREASE IN GRADIENT EXPECTED UNTIL LATE IN THE DAY OR AT NIGHT AT WHICH TIME ABOUT A 5 KT INCREASE EXPECTED IN ADDITION TO SOME GUSTINESS. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...GENERAL NORTHERLY FLOW IN THE POST FRONT REGIME BUT PRESSURE GRADIENT IS LIGHT ENOUGH THAT ANY MESOSCALE BOUNDARIES WILL OVERRIDE THE NORTHERLY WIND COMPONENT. SPEEDS WILL GENERALLY BE 10 KT OR LESS AND SEAS WILL RUN 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...TRA SHORT TERM...MBB LONG TERM...III AVIATION...JDW 000 FXUS62 KRAH 070121 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 921 PM EDT MON SEP 6 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TUESDAY. A WEAK COLD FRONT WILL CROSS THE AREA LATE WEDNESDAY. BEHIND THE FRONT... HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /THROUGH TUESDAY NIGHT/... AS OF 920 PM MONDAY... TONIGHT: ONLY COSMETIC CHANGES REQUIRED TO PREVIOUS FORECAST. MID LEVEL H5 RIDGING CENTERED OVER NORTHERN AL HAS STRENGTHENED SOME 30 METERS PER 00Z RAOBS... AND WILL CONTINUE TO BUILD EASTWARD OVERNIGHT IN THE WAKE OF A DEPARTING L/W TROUGH AXIS SITUATED JUST OFFSHORE THE EAST COAST. MEANWHILE AT THE SURFACE... A 1023 MB RIDGE JUST OFFSHORE THE TIDEWATER OF VA SHOULD CONTINUE TO REMAIN WELL ENTRENCHED ACROSS THE CAROLINAS OWING TO THE SUBSIDENCE DOWNSTREAM OF THE MID LEVEL RIDGING. GENERALLY EASTERLY FLOW AROUND THE SURFACE RIDGE FOR THE PAST 12-18 HOURS HAS RESULTED IN A MODEST RECOVERY IN LOW LEVEL MOISTURE ACROSS CENTRAL NC DURING THAT TIME... WITH DEWPOINTS RANGING AT 9 PM FROM MAINLY UPPER 50S NORTHWEST TO MIDDLE 60S SOUTH. OVERNIGHT LOWS SHOULD NOT BE TOO FAR OFF OF THOSE OBSERVED DEWPOINT TEMPERATURES... WITH MOST LOCALES EXPECTED TO DIP TO WITHIN A FEW DEGREES OF 60. THE INCREASED LOW LEVEL MOISTURE IN CONJUNCTION WITH LIGHT-CALM WINDS WITHIN THE SURFACE RIDGE AXIS... AND AN INITIALLY MOSTLY CLEAR SKY (ASIDE FROM MAINLY SCT STRATOCUMULUS TRAPPED AT THE BASE OF A SUBSIDENCE ATTENDING THE INCOMING RIDGE ALOFT)... MAY PROMOTE THE DEVELOPMENT OF PATCHES OF STRATUS AND FOG BY DAYBREAK... PARTICULARLY IN THE HIGHER DEWPOINT AIR OVER THE SOUTHERN AND SOUTHWESTERN ZONES. THIS TREND WAS ALREADY REFLECTED IN THE GRIDDED FORECAST. TUESDAY AND TUESDAY NIGHT: THE AFOREMENTIONED NORTHERN PLAINS SHORTWAVE AND ITS ASSOCIATED SURFACE LOW WILL DRIVE A COLD FRONT SOUTHEAST INTO THE OHIO VALLEY REGION ON TUESDAY. THE AIR MASS SHOULD MODERATE A BUT MORE WITH A DEVELOPING SOUTHWESTERLY FLOW AND 1000 TO 850 MILLIBAR THICKNESSES FORECAST TO RISE INTO THE 1420 TO 1425 METER RANGE. THICKNESS AND 850 MILLIBAR MIXING BOTH YIELD VALUES CONSISTENT WITH STATISTICAL GUIDANCE...88 TO 92. CONTINUED WITH DRY FORECAST AS PW RECOVERY IS FORECAST TO BE RATHER WEAK DURING THE DAY TUESDAY AND MODELS ARE NOT SHOWING MUCH DEVELOPMENT OF A PREFRONTAL TROUGH WITH HIGH PRESSURE REMAINING DOMINANT. SHOULD SEE MAINLY CLEAR SKIES TUESDAY NIGHT WITH SOUTHWESTERLY FLOW AHEAD OF WHAT LOOKS TO BE A MAINLY DRY APPROACHING COLD FRONT. HAVE LOWS WARMER THAN GUIDANCE...65 TO 67. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 235 PM MONDAY... FOR WEDNESDAY AND WEDNESDAY NIGHT: MID LEVEL VORTEX NOW PUSHING THROUGH THE DAKOTAS DEEPENS WHILE CROSSING THE UPPER GREAT LAKES TOWARD FAR SOUTHERN QUEBEC BY DAWN THURSDAY. A CORRESPONDING SURFACE FRONT PUSHES TO THE SOUTHERN APPALACHIANS BY WEDNESDAY AFTERNOON THEN DROPS SOUTHEAST THROUGH NORTH CAROLINA WEDNESDAY NIGHT... BUT WITH INCIPIENT DRY AIR (PRECIPITABLE WATER WELL UNDER ONE INCH) AND A WESTERLY DOWNSLOPE FLOW AT 850 MILLIBAR PRECEDING THE FRONT... PRECIPITATION CHANCES APPEAR LOW. WE WILL SEE PRECIPITABLE WATER VALUES INCREASE BRIEFLY TO NEAR 1.5 INCHES JUST AHEAD OF THE FRONT... AND THE NAM/GFS DO SHOW A WEAK WAVE DROPPING SOUTHEAST THROUGH THE STATE WITH THETA-E RIDGING NOSING IN AT 850 MILLIBAR. HOWEVER NO FORCING FOR ASCENT IS EVIDENT ELSEWHERE THROUGH THE TROPOSPHERE... INCLUDING AT JET LEVEL... AND THE PRECIPITATION AMOUNTS GENERATED BY THE MODELS ARE SLIM TO NONE. INSTABILITY IS ALSO LIMITED WITH THE GFS SHOWING SBCAPE PEAKING AT 500 J/KG RIGHT ALONG THE FRONT... WITH A DRY SUBCLOUD LAYER. WILL KEEP THE FORECAST DRY BUT INCLUDE A PERIOD OF ISOLATED SPRINKLES LATE AFTERNOON INTO MID EVENING AS LAPSE RATES ALOFT STEEPEN WITH BROAD MID LEVEL TROUGH PASSAGE. GIVEN THE DRY LOW LEVELS... A FEW ENHANCED GUSTS ARE POSSIBLE NEAR THESE SHOWERS. THICKNESSES CLIMB FURTHER WEDNESDAY TO AROUND 15 TO 20 METERS ABOVE NORMAL... AND WITH A DRY ADIABATIC LOW LEVEL PROFILE... HIGHS OF 89 TO 94 STILL LOOK FINE. GIVEN THE DELAY IN CLEARING OVERNIGHT ALONG WITH THE WEAK ADVECTION OF LOWER THICKNESSES AND STILL MILD AIR AT 925 TO 850 MILLIBAR... WILL BUMP LOWS UP JUST A BIT MAINLY ACROSS THE NORTH TO 64 TO 70. FOR THURSDAY AND THURSDAY NIGHT: THE FRONT IS EXPECTED TO SETTLE ALONG THE SOUTHERN BORDER OF NORTH CAROLINA THURSDAY. AN ELONGATED CANADIAN SOURCE HIGH ATTEMPTS TO BUILD IN BEHIND THE FRONT FROM THE NORTHWEST... HOWEVER THE COOLER AIR APPEARS TO BE HINDERED BY THE MOUNTAINS SUCH THAT LOW LEVEL THICKNESSES HOLD ABOVE NORMAL... AND A WEAK LEE TROUGH DEVELOPS OVER THE PIEDMONT IN THE AFTERNOON. THE COLUMN DRIES BACK OUT RATHER QUICKLY WITH NO INSTABILITY NOR LARGE SCALE LIFT... SO DO NOT ANTICIPATE ANY PRECIPITATION ALONG THE FRONTAL ZONE OR TROUGH ON THURSDAY... ALTHOUGH WE COULD SEE SOME MID OR HIGH LEVEL CLOUDINESS IN THE MORNING AS ANOTHER WEAK WAVE ALOFT DROPS THROUGH NORTH CAROLINA. HIGHS 87 TO 93. LOWS 58 TO 65 WITH A SECONDARY SURGE OF DRIER AIR DROPPING THROUGH THE STATE OVERNIGHT. -GIH && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 235 PM MONDAY... FOR FRIDAY THROUGH SATURDAY: THE FRONT TO OUR SSW TRIES TO HEAD BACK NORTHEAST AS A WARM FRONT ON FRIDAY ACCORDING TO THE LATEST GFS/ECMWF. BUT AS THE MID LEVEL VORTEX SITS AND SPINS OVER NOVA SCOTIA WITH TROUGHING ENCOMPASSING MOST OF THE EASTERN SEABOARD AND WESTERN ATLANTIC... THE BLOCKING PATTERN SHOULD HELP KEEP THE SURFACE RIDGE DOMINANT THROUGH FRIDAY NIGHT. BUT THE ECMWF (AND TO A LESSER DEGREE THE GFS) INDICATES 850 MILLIBAR NOCTURNAL JETTING NOSING INTO SOUTHWESTERN NORTH CAROLINA ALONG THE FRONT LATE FRIDAY INTO FRIDAY NIGHT... WHICH COULD INDUCE ENOUGH FORCING AND LOW LEVEL MOISTURE POOLING TO KICK OFF SLOW MOVING SHOWERS OR STORMS. THE GFS/ECMWF BOTH SUGGEST THAT THIS MOISTURE IS ROOTED IN THE REMAINS OF NOW TROPICAL STORM HERMINE... QUITE REASONABLE CONSIDERING THE MEAN FLOW PATTERN AND GOOD MODEL AGREEMENT. WILL SPREAD IN CHANCE POPS FROM SOUTHWEST TO EAST VERY LATE FRIDAY THROUGH FRIDAY NIGHT INTO SATURDAY MORNING. THE GFS/ECMWF ALSO BOTH SHOW A LOW FORMING AND TRACKING ALONG THE FRONT JUST TO OUR SOUTH... WHICH RESULTS IN AN ENHANCED NORTHEAST LOW LEVEL FLOW FRIDAY NIGHT INTO SATURDAY...POTENTIALLY RESULTING IN A WEAK IN SITU DAMMING EVENT. WHILE IT IS TOO FAR OFF WITH TOO MUCH UNCERTAINTY TO PUT MUCH FAITH IN SUCH A SCENARIO... IT WILL BE SOMETHING TO WATCH IN THE COMING DAYS. FOR NOW WILL TAPER POPS DOWN SATURDAY AFTERNOON BUT KEEP A GOOD BIT OF CLOUD COVER OVER THE AREA. WILL HAVE HIGHS NEAR NORMAL... 82 TO 88... BUT CONFIDENCE IS BELOW NORMAL AND IF THE PRECIPITATION COVERAGE IS GREATER THAN EXPECTED FRIDAY NIGHT AND SATURDAY...HIGHS COULD BE BELOW NORMAL ON SATURDAY. LOWS IN THE 60S. FOR SATURDAY NIGHT THROUGH MONDAY: THE BLOCKING VORTEX OVER NOVA SCOTIA FINALLY WEAKENS AND GETS NUDGED EASTWARD BY A STRONG SHORT WAVE NOW APPROACHING THE PACIFIC NORTHWEST. THE MID LEVEL RIDGE BETWEEN THESE TWO FEATURES DEAMPLIFIES SO IT LOOKS LIKELY THAT BROAD TROUGHING WILL BECOME REESTABLISHED OVER THE EASTERN UNITED STATES BY MONDAY. THE OPERATIONAL MODELS DIVERGE HOWEVER WITH THE ECMWF MUCH MORE AMPLIFIED THAN THE GFS... RESULTING IN THE ECMWF LEANING TOWARD KEEPING THE SURFACE FRONTAL ZONE JUST SOUTH OF THE CWA WITH COOLER TEMPERATURES AND DRY WEATHER... WHILE THE GFS ALLOWS THE WARM SECTOR TO SURGE UP INTO THE CAROLINAS WITH MUCH WARMER TEMPERATURES AND BETTER RAIN CHANCES. THE LESS AMPLIFIED GFS HAS SUPPORT FROM THE ECMWF ENSEMBLE MEAN AND THUS WAS PREFERRED. WILL HAVE LOW CHANCES OF AFTERNOON THROUGH EVENING SHOWERS OR THUNDERSTORMS... WITH TEMPERATURES GENERALLY A CATEGORY ABOVE NORMAL. -GIH && .AVIATION /23Z MONDAY THROUGH SATURDAY/... AS OF 745 PM... VFR CONDITIONS THROUGH MUCH OF THE NIGHT. STRATUS SHOULD BE MORE WIDESPREAD TOWARD DAWN THAN MONDAY MORNING... ESPECIALLY SOUTH AND WEST. LIFR CONDITIONS POSSIBLE FROM ABOUT 5 AM TO 10 AM. CONDITIONS SHOULD MOSTLY REMAIN VFR THROUGH SATURDAY...BUT THE BEST CHANCE FOR MVFR/IFR CONDITIONS EXISTS WEDNESDAY AFTERNOON INTO THURSDAY MORNING WITH THE PASSAGE OF A WEAK FRONT. FOG AND/OR LOW STRATUS IS ALSO POSSIBLE OVERNIGHT TUESDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ NEAR TERM...MWS/SMITH SHORT TERM...HARTFIELD LONG TERM...HARTFIELD 000 FXUS62 KRAH 062337 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 737 PM EDT MON SEP 6 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH TUESDAY. A WEAK COLD FRONT WILL CROSS THE AREA LATE WEDNESDAY. BEHIND THE FRONT... HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /THROUGH TUESDAY NIGHT/... AS OF 220 PM MONDAY... COVERAGE OF CUMULUS FIELD IS A LITTLE MORE EXTENSIVE THAN PREVIOUSLY FORECAST...BUT IT DOES NOT APPEAR TO BE HINDERING INSOLATION TOO MUCH TO STRAY FROM CURRENT HIGH TEMPERATURE FORECAST THIS AFTERNOON. HAVE ADJUSTED SKY COVER GRIDS TOWARD REALITY. HEIGHT RISES ALOFT WILL BEGIN THIS EVENING AS AN UPPER RIDGE BUILDS NE TOWARD THE MID ATLANTIC STATES...AHEAD OF A SHORTWAVE TROUGH LIFTING THROUGH THE NORTHERN PLAINS STATES. SURFACE HIGH PRESSURE OFF THE NEW JERSEY COAST WILL CONTINUE TO RIDGE SOUTHWEST OVER THE CAROLINAS INTO TUESDAY....WITH WEAK WARM ADVECTION AND LIGHT EAST TO SOUTHEASTERLY FLOW KICKING IN OVER THE CWA THIS EVENING. NAM CROSS SECTIONS SUGGEST UPSLOPE FROM THE LOW LEVEL FLOW AROUND THE HIGH COMBINED WITH A DECENT WARM ADVECTION PROFILE WILL BE SUFFICIENT FOR STRATUS OVER THE WESTERN HALF OF THE CWA. DEWPOINTS WILL BE STARTING OUT RATHER LOW OVER A GOOD PORTION OF THE AREA...BUT A DECENT DEWPOINT RECOVERY ACROSS THE SOUTH WITH A SOUTHEASTERLY FETCH MAY LEAD TO SOME PATCHY FOG BY TUESDAY MORNING. LOWS A COUPLE DEGREES WARMER THAN THIS PAST MORNING...59 TO 64. THE AFOREMENTIONED NORTHERN PLAINS SHORTWAVE AND ITS ASSOCIATED SURFACE LOW WILL DRIVE A COLD FRONT SOUTHEAST INTO THE OHIO VALLEY REGION ON TUESDAY. THE AIR MASS SHOULD MODERATE A BUT MORE WITH A DEVELOPING SOUTHWESTERLY FLOW AND 1000 TO 850 MILLIBAR THICKNESSES FORECAST TO RISE INTO THE 1420 TO 1425 METER RANGE. THICKNESS AND 850 MILLIBAR MIXING BOTH YIELD VALUES CONSISTENT WITH STATISTICAL GUIDANCE...88 TO 92. CONTINUED WITH DRY FORECAST AS PW RECOVERY IS FORECAST TO BE RATHER WEAK DURING THE DAY TUESDAY AND MODELS ARE NOT SHOWING MUCH DEVELOPMENT OF A PREFRONTAL TROUGH WITH HIGH PRESSURE REMAINING DOMINANT. SHOULD SEE MAINLY CLEAR SKIES TUESDAY NIGHT WITH SOUTHWESTERLY FLOW AHEAD OF WHAT LOOKS TO BE A MAINLY DRY APPROACHING COLD FRONT. HAVE LOWS WARMER THAN GUIDANCE...65 TO 67. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 235 PM MONDAY... FOR WEDNESDAY AND WEDNESDAY NIGHT: MID LEVEL VORTEX NOW PUSHING THROUGH THE DAKOTAS DEEPENS WHILE CROSSING THE UPPER GREAT LAKES TOWARD FAR SOUTHERN QUEBEC BY DAWN THURSDAY. A CORRESPONDING SURFACE FRONT PUSHES TO THE SOUTHERN APPALACHIANS BY WEDNESDAY AFTERNOON THEN DROPS SOUTHEAST THROUGH NORTH CAROLINA WEDNESDAY NIGHT... BUT WITH INCIPIENT DRY AIR (PRECIPITABLE WATER WELL UNDER ONE INCH) AND A WESTERLY DOWNSLOPE FLOW AT 850 MILLIBAR PRECEDING THE FRONT... PRECIPITATION CHANCES APPEAR LOW. WE WILL SEE PRECIPITABLE WATER VALUES INCREASE BRIEFLY TO NEAR 1.5 INCHES JUST AHEAD OF THE FRONT... AND THE NAM/GFS DO SHOW A WEAK WAVE DROPPING SOUTHEAST THROUGH THE STATE WITH THETA-E RIDGING NOSING IN AT 850 MILLIBAR. HOWEVER NO FORCING FOR ASCENT IS EVIDENT ELSEWHERE THROUGH THE TROPOSPHERE... INCLUDING AT JET LEVEL... AND THE PRECIPITATION AMOUNTS GENERATED BY THE MODELS ARE SLIM TO NONE. INSTABILITY IS ALSO LIMITED WITH THE GFS SHOWING SBCAPE PEAKING AT 500 J/KG RIGHT ALONG THE FRONT... WITH A DRY SUBCLOUD LAYER. WILL KEEP THE FORECAST DRY BUT INCLUDE A PERIOD OF ISOLATED SPRINKLES LATE AFTERNOON INTO MID EVENING AS LAPSE RATES ALOFT STEEPEN WITH BROAD MID LEVEL TROUGH PASSAGE. GIVEN THE DRY LOW LEVELS... A FEW ENHANCED GUSTS ARE POSSIBLE NEAR THESE SHOWERS. THICKNESSES CLIMB FURTHER WEDNESDAY TO AROUND 15 TO 20 METERS ABOVE NORMAL... AND WITH A DRY ADIABATIC LOW LEVEL PROFILE... HIGHS OF 89 TO 94 STILL LOOK FINE. GIVEN THE DELAY IN CLEARING OVERNIGHT ALONG WITH THE WEAK ADVECTION OF LOWER THICKNESSES AND STILL MILD AIR AT 925 TO 850 MILLIBAR... WILL BUMP LOWS UP JUST A BIT MAINLY ACROSS THE NORTH TO 64 TO 70. FOR THURSDAY AND THURSDAY NIGHT: THE FRONT IS EXPECTED TO SETTLE ALONG THE SOUTHERN BORDER OF NORTH CAROLINA THURSDAY. AN ELONGATED CANADIAN SOURCE HIGH ATTEMPTS TO BUILD IN BEHIND THE FRONT FROM THE NORTHWEST... HOWEVER THE COOLER AIR APPEARS TO BE HINDERED BY THE MOUNTAINS SUCH THAT LOW LEVEL THICKNESSES HOLD ABOVE NORMAL... AND A WEAK LEE TROUGH DEVELOPS OVER THE PIEDMONT IN THE AFTERNOON. THE COLUMN DRIES BACK OUT RATHER QUICKLY WITH NO INSTABILITY NOR LARGE SCALE LIFT... SO DO NOT ANTICIPATE ANY PRECIPITATION ALONG THE FRONTAL ZONE OR TROUGH ON THURSDAY... ALTHOUGH WE COULD SEE SOME MID OR HIGH LEVEL CLOUDINESS IN THE MORNING AS ANOTHER WEAK WAVE ALOFT DROPS THROUGH NORTH CAROLINA. HIGHS 87 TO 93. LOWS 58 TO 65 WITH A SECONDARY SURGE OF DRIER AIR DROPPING THROUGH THE STATE OVERNIGHT. -GIH && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 235 PM MONDAY... FOR FRIDAY THROUGH SATURDAY: THE FRONT TO OUR SSW TRIES TO HEAD BACK NORTHEAST AS A WARM FRONT ON FRIDAY ACCORDING TO THE LATEST GFS/ECMWF. BUT AS THE MID LEVEL VORTEX SITS AND SPINS OVER NOVA SCOTIA WITH TROUGHING ENCOMPASSING MOST OF THE EASTERN SEABOARD AND WESTERN ATLANTIC... THE BLOCKING PATTERN SHOULD HELP KEEP THE SURFACE RIDGE DOMINANT THROUGH FRIDAY NIGHT. BUT THE ECMWF (AND TO A LESSER DEGREE THE GFS) INDICATES 850 MILLIBAR NOCTURNAL JETTING NOSING INTO SOUTHWESTERN NORTH CAROLINA ALONG THE FRONT LATE FRIDAY INTO FRIDAY NIGHT... WHICH COULD INDUCE ENOUGH FORCING AND LOW LEVEL MOISTURE POOLING TO KICK OFF SLOW MOVING SHOWERS OR STORMS. THE GFS/ECMWF BOTH SUGGEST THAT THIS MOISTURE IS ROOTED IN THE REMAINS OF NOW TROPICAL STORM HERMINE... QUITE REASONABLE CONSIDERING THE MEAN FLOW PATTERN AND GOOD MODEL AGREEMENT. WILL SPREAD IN CHANCE POPS FROM SOUTHWEST TO EAST VERY LATE FRIDAY THROUGH FRIDAY NIGHT INTO SATURDAY MORNING. THE GFS/ECMWF ALSO BOTH SHOW A LOW FORMING AND TRACKING ALONG THE FRONT JUST TO OUR SOUTH... WHICH RESULTS IN AN ENHANCED NORTHEAST LOW LEVEL FLOW FRIDAY NIGHT INTO SATURDAY... POTENTIALLY RESULTING IN A WEAK IN SITU DAMMING EVENT. WHILE IT IS TOO FAR OFF WITH TOO MUCH UNCERTAINTY TO PUT MUCH FAITH IN SUCH A SCENARIO... IT WILL BE SOMETHING TO WATCH IN THE COMING DAYS. FOR NOW WILL TAPER POPS DOWN SATURDAY AFTERNOON BUT KEEP A GOOD BIT OF CLOUD COVER OVER THE AREA. WILL HAVE HIGHS NEAR NORMAL... 82 TO 88... BUT CONFIDENCE IS BELOW NORMAL AND IF THE PRECIPITATION COVERAGE IS GREATER THAN EXPECTED FRIDAY NIGHT AND SATURDAY... HIGHS COULD BE BELOW NORMAL ON SATURDAY. LOWS IN THE 60S. FOR SATURDAY NIGHT THROUGH MONDAY: THE BLOCKING VORTEX OVER NOVA SCOTIA FINALLY WEAKENS AND GETS NUDGED EASTWARD BY A STRONG SHORT WAVE NOW APPROACHING THE PACIFIC NORTHWEST. THE MID LEVEL RIDGE BETWEEN THESE TWO FEATURES DEAMPLIFIES SO IT LOOKS LIKELY THAT BROAD TROUGHING WILL BECOME REESTABLISHED OVER THE EASTERN UNITED STATES BY MONDAY. THE OPERATIONAL MODELS DIVERGE HOWEVER WITH THE ECMWF MUCH MORE AMPLIFIED THAN THE GFS... RESULTING IN THE ECMWF LEANING TOWARD KEEPING THE SURFACE FRONTAL ZONE JUST SOUTH OF THE CWA WITH COOLER TEMPERATURES AND DRY WEATHER... WHILE THE GFS ALLOWS THE WARM SECTOR TO SURGE UP INTO THE CAROLINAS WITH MUCH WARMER TEMPERATURES AND BETTER RAIN CHANCES. THE LESS AMPLIFIED GFS HAS SUPPORT FROM THE ECMWF ENSEMBLE MEAN AND THUS WAS PREFERRED. WILL HAVE LOW CHANCES OF AFTERNOON THROUGH EVENING SHOWERS OR THUNDERSTORMS... WITH TEMPERATURES GENERALLY A CATEGORY ABOVE NORMAL. -GIH && .AVIATION /23Z MONDAY THROUGH SATURDAY/... AS OF 745 PM... VFR CONDITIONS THROUGH MUCH OF THE NIGHT. STRATUS SHOULD BE MORE WIDESPREAD TOWARD DAWN THAN MONDAY MORNING... ESPECIALLY SOUTH AND WEST. LIFR CONDITIONS POSSIBLE FROM ABOUT 5 AM TO 10 AM. CONDITIONS SHOULD MOSTLY REMAIN VFR THROUGH SATURDAY...BUT THE BEST CHANCE FOR MVFR/IFR CONDITIONS EXISTS WEDNESDAY AFTERNOON INTO THURSDAY MORNING WITH THE PASSAGE OF A WEAK FRONT. FOG AND/OR LOW STRATUS IS ALSO POSSIBLE OVERNIGHT TUESDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ NEAR TERM...SMITH SHORT TERM...HARTFIELD LONG TERM...HARTFIELD 000 FXUS62 KILM 062321 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 721 PM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE MIDDLE OF NEXT WEEK. A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN CHANCES. A WARM FRONT MAY BRING SOME BETTER RAIN CHANCES OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM MONDAY...HIGH PRESSURE JUST NORTH OF AREA WILL CONTINUE TO PRODUCE E-NE FLOW OVER THE COASTAL CAROLINAS. WAVE ALONG OLD FRONT LOCATED JUST OFF SHORE WITH VERY SHARP MOISTURE GRADIENT ALIGNED JUST ALONG THE COAST. RUC SHOWING CLOSE TO 1.75 INCHES OF PCP WATER LOCATED OFF THE SC COAST BUT LESS THAN AN INCH OVER INLAND COUNTIES. WATER VAPOR IMAGERY SHOWING THIS MOISTURE GRADIENT VERY NICELY ALIGNED ALONG THE SOUTH CAROLINA COAST. SHORTWAVE RIDING ACROSS THE AREA HELPED TO TRIGGER SOME ISOLD SHWRS/TSTMS IN THIS MOISTURE RICH AIR. THIS MOISTURE BOUNDARY SHOULD GET PUSHED FARTHER OFF SHORE WITH PCP WATER VALUES DROPPING DOWN TO LESS THAN 1.25 INCHES ALONG TO THE COAST THROUGH THIS EVENING. AT THE SAME TIME THE SEA BREEZE WILL GET AN EXTRA PUSH FROM PREVAILING E-NE WINDS MOVING INLAND DRAGGING IN SOME OF THE MOISTURE RICH AIR. OVERALL EXPECT SHWR/TSTM ACTIVITY TO DECREASE OVER LOCAL AREA THROUGH LATE THIS AFTN AND RELOCATE FARTHER OFF SHORE IN THE COASTAL WATERS. BUT SOME OF THE OUTFLOW BOUNDARIES WILL INTERACT WITH SEA BREEZE BOUNDARY TO PRODUCE A FEW SHOWERS MAINLY OVER COASTAL SOUTH CAROLINA COUNTIES BUT MAY SEE A FEW LINGERING OVER BRUNSWICK COUNTY TO THE VERY SOUTHERN TIP OF CAPE FEAR. AS HEATING CUTS OFF AND BOUNDARY SHIFTS FARTHER OFF SHORE THROUGH TONIGHT CLDS/SHWRS SHOULD DISSIPATE. THIS WILL BE AIDED BY A RIDGE BUILDING ALOFT THROUGH TUES MORNING. COUNTING ON CLOUDS DISSIPATING THROUGH THE NIGHT WITH DRIER AIR OVERALL AND LIGHT TO CALM WINDS. THEREFORE WILL HAVE DECENT RADIATIONAL COOLING OVER INLAND AND NC ZONES. THE SC COAST WILL HAVE THE HIGHEST TEMPS CLOSER 70 WHILE OTHER PLACES SHOULD GET DOWN TO THE LOW TO MID 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...A WARM TUESDAY ON TAP AS UPPER LEVEL RIDGE FLATTENS BUT HOLDS ON ACROSS THE CAROLINAS. HIGH PRESSURE AT THE SFC LOCATED OFF OF CAPE HATTERAS AND A TROUGH DEVELOPING EAST OF JACKSONVILLE, FL. SKY COVER FAIRLY MINIMAL THANKS TO THE SINKING AIR SUPPLIED BY THE RIDGE ALOFT BUT THE SURFACE TROUGH TO THE SOUTH MAY DRAW IN ENOUGH MOISTURE OVER SRN ZONES TO WARRANT A PARTLY CLOUDY FORECAST. THE UPPER RIDGE FLATTENS AND WEAKENS SUFFICIENTLY ON WEDNESDAY TO ALLOW A COLD FRONT TO APPROACH FROM THE NW. THIS BOUNDARY WILL SLOWLY CROSS THE FORECAST AREA WEDNESDAY NIGHT. WITH A DIURNALLY UNFAVORABLE TIME FOR INSTABILITY AND WEAK FORCING PRECIPITATION WILL BE HARD PRESSED TO DEVELOP. SLIGHT CHANCE POPS ALONG THE COAST FOR SHOWERS AND LOW END CHANCE POPS FOR DEEPER CONVECTION OVER WATER WHERE HEAT AND MOISTURE SOURCES ARE BETTER. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 PM MONDAY...COLD FRONT IN THE AREA THU MORNING WILL CONTINUE SLOWLY MOVING SOUTH INTO FRI AS 5H RIDGE CONTINUES TO BREAK DOWN. REMAINS OF FRONT STALLS JUST SOUTH OF THE AREA FRI AND LINGERS THERE THROUGH SAT. AT THE SAME TIME MOISTURE AND DYNAMICS FROM THE REMAINS OF TS HERMINE ROUND THE TOP OF THE WEAKENING RIDGE AND PASS OVER THE AREA. PRECIPITABLE WATER VALUES RISE ABOVE 2 INCHES FRI NIGHT INTO SAT AND SOUNDINGS SUGGEST SOME ELEVATED CONVECTION COULD DEVELOP FRI NIGHT. TIMING OF HERMINE REMAINS WILL PLAY A LARGE ROLE IN STORM COVERAGE SAT. LATEST GFS/ECMWF TIMING WOULD HAVE BEST DYNAMICS ARRIVING COINCIDENT WITH MAX HEATING ON SAT WHICH COULD LEAD TO GREATER STORM COVERAGE. STALLED FRONT LIFTS NORTH AS A WARM FRONT SAT NIGHT INTO SUN. PWATS REMAIN ABOVE 2 INCHES THROUGH THE END OF THE PERIOD AND DIURNAL HEATING COULD PRODUCE AFTERNOON SHOWERS AND T-STORMS ON SUN AND MON. GFS HINTING AT A SHORTWAVE OR TWO IN NEARLY ZONAL FLO AT THE END OF THE PERIOD BUT CONFIDENCE IN THESE FEATURES IS LIMITED. KEEPING TEMPERATURES ABOVE CLIMO...THOUGH NOT AS WARM AS FORECAST YESTERDAY. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... AS OF 00Z...MODERATE CONFIDENCE FORECAST THROUGH THE VALID PERIOD DUE TO POTENTIAL FOG AND/OR STRATUS OVERNIGHT. DIURNAL CU IS RAPIDLY DISSIPATING THIS EVE...AND SKC WILL BECOME THE SKY CONDITION IN THE NEXT FEW HOURS. SEA BREEZE HAS PENETRATED WELL INLAND...WHICH IS ACTING TO INCREASE SURFACE MOISTURE AS EVIDENCED BY RISING TD/S. ALTHOUGH WINDS WILL REMAIN ELEVATED AND GUSTY FOR THE NEXT FEW HOURS...THEY WILL GO TO NEAR CALM OVERNIGHT...WHICH WHEN COMBINED WITH CLEAR SKY CONDITIONS AND HIGH SURFACE MOISTURE PRESENTS AN OBVIOUS FOG/STRATUS THREAT OVERNIGHT. CONFIDENCE IS FAIRLY HIGH THAT AT LEAST MVFR FOG WILL DEVELOP INLAND...AND HAVE ALSO INTRODUCED TEMPO IFR TO LBT/FLO TOWARDS DAYBREAK TUESDAY. ALTHOUGH XOVERS WILL PROBABLY NOT QUITE BE MET...MOISTURE ADVECTION THIS EVE WILL LIKELY RAISE TD/S ENOUGH THAT DEWPOINT DEPRESSIONS WILL BECOME MINIMIZED OVERNIGHT. AT THE COAST THE FORECAST IS A LITTLE TRICKIER SINCE BUFR PROFILES INDICATE THE DEVELOPMENT OF A WEAK...BUT STILL PRESENT...LLJ JUST ABOVE THE B/L. THIS MAY PRODUCE MORE OF A STRATUS ISSUE...AND BUFR PROFILES ARE INDICATING MORE STRATUS THAN FOG AT THE COAST. FOR NOW...HAVE MVFR VSBYS WITH SCT AT MVFR LEVELS AT THE COAST...WITH THE HIGHEST CHANCE OF STRATUS BEING AT THE MYRTLES WHERE TD/S ARE CURRENTLY IN THE LOW 70S. WILL WATCH DEVELOPMENT THIS EVE...AND UPDATE WITH 06Z ISSUANCE AS NECESSARY AND AS CONFIDENCE INCREASES. AFTER SUNRISE TUESDAY FOG WILL BURN OFF AND SOME EARLY MORNING STRATOCU WILL LIKELY DEVELOP. AS RIDGE ALOFT FINALLY BUILDS OVERHEAD...SUBSIDENCE CAP WILL HELP ERODE/INHIBIT MUCH CLOUD DEVELOPMENT DURING THE AFTN...AND ANTICIPATE NEARLY CLOUDLESS SKY CONDITIONS NEAR THE COAST. INLAND MAY SEE SOME AFTN DIURNAL CU WITH SIGNIFICANT AFTN HEATING. WINDS THROUGH THE DAY WILL VEER NE TO SE...AND INCREASE TO AROUND 10 KTS. EXTENDED OUTLOOK...MORNING FOG POSSIBLE EACH MORNING. COLD FRONT WILL APPROACH THE AREA THURSDAY WITH A SLIGHT CHANCE OF SHOWERS. MORE SHOWERS ARE POSSIBLE SATURDAY WITH THE ADVANCE OF A WARM FRONT. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM MONDAY...LIGHT ON SHORE NE-E FLOW WILL EXIST AROUND HIGH PRESSURE CENTERED TO NORTH OF COASTAL WATERS. SEAS WILL CONTINUE TO BE 3 FT OR LESS OVER MOST WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...AS OFFSHORE HIGH WEAKENS AND PULLS EASTWARD SLIGHTLY WINDS WILL TURN TO THE EAST AS THEY REMAIN CAPPED AT 10 KT. A SFC TROUGH DEVELOPING EAST OF NRN FLORIDA WILL ALSO AID IN THIS VEER IN DIRECTION FROM NE TO E. WITH SUCH LIGHT WINDS AND THE ABSENCE OF ANY SIGNIFICANT GROUND SWELL SEAS WILL AVERAGE 2 FT OR LESS. AN APPROACHING COLD FRONT WILL TURN FLOW TO SOUTHWESTERLY ON WEDNESDAY BUT NO REAL INCREASE IN GRADIENT EXPECTED UNTIL LATE IN THE DAY OR AT NIGHT AT WHICH TIME ABOUT A 5 KT INCREASE EXPECTED IN ADDITION TO SOME GUSTINESS. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...GENERAL NORTHERLY FLOW IN THE POST FRONT REGIME BUT PRESSURE GRADIENT IS LIGHT ENOUGH THAT ANY MESOSCALE BOUNDARIES WILL OVERRIDE THE NORTHERLY WIND COMPONENT. SPEEDS WILL GENERALLY BE 10 KT OR LESS AND SEAS WILL RUN 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...RGZ SHORT TERM...MBB LONG TERM...III AVIATION...JDW 000 FXUS62 KILM 061902 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 302 PM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH THE MIDDLE OF NEXT WEEK. A COLD FRONT WEDNESDAY NIGHT IS NOT EXPECTED TO BRING ANY SIGNIFICANT RAIN CHANCES. A WARM FRONT MAY BRING SOME BETTER RAIN CHANCES OVER THE WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM MONDAY...HIGH PRESSURE JUST NORTH OF AREA WILL CONTINUE TO PRODUCE E-NE FLOW OVER THE COASTAL CAROLINAS. WAVE ALONG OLD FRONT LOCATED JUST OFF SHORE WITH VERY SHARP MOISTURE GRADIENT ALIGNED JUST ALONG THE COAST. RUC SHOWING CLOSE TO 1.75 INCHES OF PCP WATER LOCATED OFF THE SC COAST BUT LESS THAN AN INCH OVER INLAND COUNTIES. WATER VAPOR IMAGERY SHOWING THIS MOISTURE GRADIENT VERY NICELY ALIGNED ALONG THE SOUTH CAROLINA COAST. SHORTWAVE RIDING ACROSS THE AREA HELPED TO TRIGGER SOME ISOLD SHWRS/TSTMS IN THIS MOISTURE RICH AIR. THIS MOISTURE BOUNDARY SHOULD GET PUSHED FARTHER OFF SHORE WITH PCP WATER VALUES DROPPING DOWN TO LESS THAN 1.25 INCHES ALONG TO THE COAST THROUGH THIS EVENING. AT THE SAME TIME THE SEA BREEZE WILL GET AN EXTRA PUSH FROM PREVAILING E-NE WINDS MOVING INLAND DRAGGING IN SOME OF THE MOISTURE RICH AIR. OVERALL EXPECT SHWR/TSTM ACTIVITY TO DECREASE OVER LOCAL AREA THROUGH LATE THIS AFTN AND RELOCATE FARTHER OFF SHORE IN THE COASTAL WATERS. BUT SOME OF THE OUTFLOW BOUNDARIES WILL INTERACT WITH SEA BREEZE BOUNDARY TO PRODUCE A FEW SHOWERS MAINLY OVER COASTAL SOUTH CAROLINA COUNTIES BUT MAY SEE A FEW LINGERING OVER BRUNSWICK COUNTY TO THE VERY SOUTHERN TIP OF CAPE FEAR. AS HEATING CUTS OFF AND BOUNDARY SHIFTS FARTHER OFF SHORE THROUGH TONIGHT CLDS/SHWRS SHOULD DISSIPATE. THIS WILL BE AIDED BY A RIDGE BUILDING ALOFT THROUGH TUES MORNING. COUNTING ON CLOUDS DISSIPATING THROUGH THE NIGHT WITH DRIER AIR OVERALL AND LIGHT TO CALM WINDS. THEREFORE WILL HAVE DECENT RADIATIONAL COOLING OVER INLAND AND NC ZONES. THE SC COAST WILL HAVE THE HIGHEST TEMPS CLOSER 70 WHILE OTHER PLACES SHOULD GET DOWN TO THE LOW TO MID 60S. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...A WARM TUESDAY ON TAP AS UPPER LEVEL RIDGE FLATTENS BUT HOLDS ON ACROSS THE CAROLINAS. HIGH PRESSURE AT THE SFC LOCATED OFF OF CAPE HATTERAS AND A TROUGH DEVELOPING EAST OF JACKSONVILLE, FL. SKY COVER FAIRLY MINIMAL THANKS TO THE SINKING AIR SUPPLIED BY THE RIDGE ALOFT BUT THE SURFACE TROUGH TO THE SOUTH MAY DRAW IN ENOUGH MOISTURE OVER SRN ZONES TO WARRANT A PARTLY CLOUDY FORECAST. THE UPPER RIDGE FLATTENS AND WEAKENS SUFFICIENTLY ON WEDNESDAY TO ALLOW A COLD FRONT TO APPROACH FROM THE NW. THIS BOUNDARY WILL SLOWLY CROSS THE FORECAST AREA WEDNESDAY NIGHT. WITH A DIURNALLY UNFAVORABLE TIME FOR INSTABILITY AND WEAK FORCING PRECIPITATION WILL BE HARD PRESSED TO DEVELOP. SLIGHT CHANCE POPS ALONG THE COAST FOR SHOWERS AND LOW END CHANCE POPS FOR DEEPER CONVECTION OVER WATER WHERE HEAT AND MOISTURE SOURCES ARE BETTER. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 3 PM MONDAY...COLD FRONT IN THE AREA THU MORNING WILL CONTINUE SLOWLY MOVING SOUTH INTO FRI AS 5H RIDGE CONTINUES TO BREAK DOWN. REMAINS OF FRONT STALLS JUST SOUTH OF THE AREA FRI AND LINGERS THERE THROUGH SAT. AT THE SAME TIME MOISTURE AND DYNAMICS FROM THE REMAINS OF TS HERMINE ROUND THE TOP OF THE WEAKENING RIDGE AND PASS OVER THE AREA. PRECIPITABLE WATER VALUES RISE ABOVE 2 INCHES FRI NIGHT INTO SAT AND SOUNDINGS SUGGEST SOME ELEVATED CONVECTION COULD DEVELOP FRI NIGHT. TIMING OF HERMINE REMAINS WILL PLAY A LARGE ROLE IN STORM COVERAGE SAT. LATEST GFS/ECMWF TIMING WOULD HAVE BEST DYNAMICS ARRIVING COINCIDENT WITH MAX HEATING ON SAT WHICH COULD LEAD TO GREATER STORM COVERAGE. STALLED FRONT LIFTS NORTH AS A WARM FRONT SAT NIGHT INTO SUN. PWATS REMAIN ABOVE 2 INCHES THROUGH THE END OF THE PERIOD AND DIURNAL HEATING COULD PRODUCE AFTERNOON SHOWERS AND T-STORMS ON SUN AND MON. GFS HINTING AT A SHORTWAVE OR TWO IN NEARLY ZONAL FLO AT THE END OF THE PERIOD BUT CONFIDENCE IN THESE FEATURES IS LIMITED. KEEPING TEMPERATURES ABOVE CLIMO...THOUGH NOT AS WARM AS FORECAST YESTERDAY. && .AVIATION /18Z MONDAY THROUGH FRIDAY/... AS OF 18Z...WATER VAPOR IMAGERY CONTINUES TO SHOW VERY DRY AIR JUST INLAND OF THE IMMEDIATE COAST. SHOWERS ARE OCCURRING TO THE SOUTHWEST AND SOUTH OF MYR...WITH ISOLATED THUNDERSTORMS IN THE COASTAL WATERS WELL EAST AND SOUTHEAST OF THE MYR/CRE TERMINALS. HIGH CONFIDENCE VFR FORECAST FOR ALL TERMINALS THROUGH THIS EVENING. EAST TO SOUTHEAST WINDS AT 8-15 KNOTS...HIGHEST AT THE COASTAL TERMINALS WILL CONTINUE THROUGH THE AFTERNOON. MODELS ARE DEPICTING THE DEEPEST MOISTURE WILL REMAIN EAST OF THE TERMINALS THIS AFTERNOON...AND BELIEVE THIS IS WHERE THE BEST THUNDERSTORM POTENTIAL WILL REMAIN. BUT EASTERLY WINDS IN THE LOW LEVELS IS CONTINUING TO ADVECT LOW LEVEL MOISTURE INLAND. THIS ALONG WITH A RESULTANT BOUNDARY SHOULD COMBINE TO ALLOW SHOWERS TO DEVELOP THROUGH THE AFTERNOON...MOST LIKELY JUST INLAND OF MYR/CRE. LIMITED INSTABILITY...DRY AIR...WEAK CAPPING AND LACK OF LARGE SCALE LIFT SHOULD KEEP ACTIVITY ISOLATED AND NEGATE ANY THUNDERSTORM DEVELOPMENT INLAND AREAS. SOME OF THE SHOWERS COULD APPROACH THE FLO TERMINAL BY LATE AFTERNOON AS THE BOUNDARY MOVES FURTHER INLAND. BUT THE AIRMASS WILL BE BECOMING INCREASINGLY STABLE AS THE AFTERNOON PROGRESSES...SO EXPECTED SHOWER ACTIVITY TO DISSIPATE BEFORE REACHING THE FLO TERMINAL LATE AFTERNOON/SUNSET. BY SUNSET WINDS SHOULD BECOME LIGHT AND VARIABLE AT FLO/LBT AND AT THE COASTAL TERMINALS BY 02-03Z. TIME HEIGHT IMAGES SUGGEST A POSSIBILITY OF MVFR CEILINGS 1-2K DEVELOPING AFTER MIDNIGHT. THERE IS LOW CONFIDENCE OF OCCURRENCE ATTM. FOG DEVELOPMENT SEEMS MORE LIKELY WITH MODERATE CONFIDENCE THAT MVFR VISIBILITIES WILL DEVELOP. IFR VISIBILITIES COULD DEVELOP AT THE FLO/LBT TERMINALS...BUT CONFIDENCE IS LOW ATTM. BUT IF A SHOWER OCCURS AT THE FLO TERMINAL THIS AFTERNOON THEN IFR POTENTIAL WILL BECOME MORE LIKELY. WILL INDICATE MVFR VISIBILITIES DEVELOPING AT ALL TERMINALS AFTER MIDNIGHT. VFR EXPECTED TUESDAY MORNING AFTER SUNRISE WITH NORTHEAST TO EAST WINDS AROUND 5 KNOTS BECOMING EAST TO SOUTHEAST AT 10-15 KNOTS BY MID MORNING. EXTENDED OUTLOOK...LOW CONFIDENCE IFR VISIBILITIES DUE TO EARLY MORNING FOG EACH MORNING AT FLO/LBT. OTHERWISE...NO SIG WX EXPECTED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM MONDAY...LIGHT ON SHORE NE-E FLOW WILL EXIST AROUND HIGH PRESSURE CENTERED TO NORTH OF COASTAL WATERS. SEAS WILL CONTINUE TO BE 3 FT OR LESS OVER MOST WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3 PM MONDAY...AS OFFSHORE HIGH WEAKENS AND PULLS EASTWARD SLIGHTLY WINDS WILL TURN TO THE EAST AS THEY REMAIN CAPPED AT 10 KT. A SFC TROUGH DEVELOPING EAST OF NRN FLORIDA WILL ALSO AID IN THIS VEER IN DIRECTION FROM NE TO E. WITH SUCH LIGHT WINDS AND THE ABSENCE OF ANY SIGNIFICANT GROUND SWELL SEAS WILL AVERAGE 2 FT OR LESS. AN APPROACHING COLD FRONT WILL TURN FLOW TO SOUTHWESTERLY ON WEDNESDAY BUT NO REAL INCREASE IN GRADIENT EXPECTED UNTIL LATE IN THE DAY OR AT NIGHT AT WHICH TIME ABOUT A 5 KT INCREASE EXPECTED IN ADDITION TO SOME GUSTINESS. LONG TERM /THURSDAY THROUGH SATURDAY/... AS OF 3 PM MONDAY...GENERAL NORTHERLY FLOW IN THE POST FRONT REGIME BUT PRESSURE GRADIENT IS LIGHT ENOUGH THAT ANY MESOSCALE BOUNDARIES WILL OVERRIDE THE NORTHERLY WIND COMPONENT. SPEEDS WILL GENERALLY BE 10 KT OR LESS AND SEAS WILL RUN 2 TO 3 FT. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MBB NEAR TERM...RGZ SHORT TERM...MBB LONG TERM...III AVIATION...MRR 000 FXUS62 KRAH 061836 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 235 PM EDT MON SEP 6 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NC THROUGH TUESDAY. A WEAK COLD FRONT WILL CROSS THE AREA LATE WEDNESDAY. BEHIND THE FRONT... HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THE REMAINDER OF THE WORK WEEK. && .NEAR TERM /THROUGH TUESDAY NIGHT/... AS OF 220 PM MONDAY... COVERAGE OF CU FIELD IS A LITTLE MORE EXTENSIVE THAN PREVIOUSLY FORECAST...BUT IT DOESN`T APPEAR TO BE HINDERING INSOLATION TOO MUCH TO STRAY FROM CURRENT HIGH TEMP FORECAST THIS AFTERNOON. HAVE ADJUSTED SKY COVER GRIDS TOWARD REALITY. HEIGHT RISES ALOFT WILL BEGIN THIS EVENING AS AN UPPER RIDGE BUILDS NE TOWARD THE MID ATLANTIC STATES...AHEAD OF A SHORTWAVE TROUGH LIFTING THROUGH THE NORTHERN PLAINS STATES. SURFACE HIGH PRESSURE OFF THE NJ COAST WILL CONTINUE TO RIDGE SW OVER THE CAROLINAS INTO TUESDAY....WITH WEAK WARM ADVECTION AND LIGHT EAST-SOUTHEASTERLY FLOW KICKING IN OVER THE CWA THIS EVENING. NAM CROSS-SECTIONS SUGGEST UPSLOPE FROM THE LOW LEVEL FLOW AROUND THE HIGH COMBINED WITH A DECENT WARM ADVECTION PROFILE WILL BE SUFFICIENT FOR STRATUS OVER THE WESTERN HALF OF THE CWA. DEWPOINTS WILL BE STARTING OUT RATHER LOW OVER A GOOD PORTION OF THE AREA...BUT A DECENT DEWPOINT RECOVERY ACROSS THE SOUTH WITH A SOUTHEASTERLY FETCH MAY LEAD TO SOME PATCHY FOG BY TUESDAY MORNING. LOWS A COUPLE DEGREES WARMER THAN THIS PAST MORNING...59-64. THE AFOREMENTIONED NORTHERN PLAINS SHORTWAVE AND ITS ASSOCIATED SURFACE LOW WILL DRIVE A COLD FRONT SE INTO THE OHIO VALLEY REGION ON TUESDAY. THE AIRMASS SHOULD MODERATE A BUT MORE WITH A DEVELOPING SOUTHWESTERLY FLOW AND 1000-850MB THICKNESSES PROGGED TO RISE INTO THE 1420-1425M RANGE. THICKNESS AND 850MB MIXING BOTH YIELD VALUES CONSISTENT WITH STATISTICAL GUIDANCE...88-92. CONTINUED WITH DRY FORECAST AS PW RECOVERY IS FORECAST TO BE RATHER WEAK DURING THE DAY TUESDAY AND MODELS ARE NOT SHOWING MUCH DEVELOPMENT OF A PREFRONTAL TROUGH WITH HIGH PRESSURE REMAINING DOMINANT. SHOULD SEE MAINLY CLEAR SKIES TUESDAY NIGHT WITH SOUTHWESTERLY FLOW AHEAD OF WHAT LOOKS TO BE A MAINLY DRY APPROACHING COLD FRONT. HAVE LOWS WARMER THAN GUIDANCE...65-67. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 235 PM MONDAY... FOR WEDNESDAY/WEDNESDAY NIGHT: MID LEVEL VORTEX NOW PUSHING THROUGH THE DAKOTAS DEEPENS WHILE CROSSING THE UPPER GREAT LAKES TOWARD FAR SRN QUEBEC BY DAWN THURSDAY. A CORRESPONDING SURFACE FRONT PUSHES TO THE SRN APPALACHIANS BY WEDNESDAY AFTERNOON THEN DROPS SE THROUGH NC WEDNESDAY NIGHT... BUT WITH INCIPIENT DRY AIR (PW WELL UNDER 1") AND A WESTERLY DOWNSLOPE FLOW AT 850 MB PRECEDING THE FRONT... PRECIP CHANCES APPEAR LOW. WE WILL SEE PW VALUES INCREASE BRIEFLY TO NEAR 1.5" JUST AHEAD OF THE FRONT... AND THE NAM/GFS DO SHOW A WEAK WAVE DROPPING SE THROUGH THE STATE WITH THETA-E RIDGING NOSING IN AT 850 MB. HOWEVER NO FORCING FOR ASCENT IS EVIDENT ELSEWHERE THROUGH THE TROPOSPHERE... INCLUDING AT JET LEVEL... AND THE PRECIP AMOUNTS GENERATED BY THE MODELS ARE SLIM TO NONE. INSTABILITY IS ALSO LIMITED WITH THE GFS SHOWING SBCAPE PEAKING AT 500 J/KG RIGHT ALONG THE FRONT... WITH A DRY SUBCLOUD LAYER. WILL KEEP THE FORECAST DRY BUT INCLUDE A PERIOD OF ISOLATED SPRINKLES LATE AFTERNOON INTO MID EVENING AS LAPSE RATES ALOFT STEEPEN WITH BROAD MID LEVEL TROUGH PASSAGE. GIVEN THE DRY LOW LEVELS... A FEW ENHANCED GUSTS ARE POSSIBLE NEAR THESE SHOWERS. THICKNESSES CLIMB FURTHER WEDNESDAY TO AROUND 15-20 M ABOVE NORMAL... AND WITH A DRY ADIABATIC LOW LEVEL PROFILE... HIGHS OF 89-94 STILL LOOK FINE. GIVEN THE DELAY IN CLEARING OVERNIGHT ALONG WITH THE WEAK ADVECTION OF LOWER THICKNESSES AND STILL-MILD AIR AT 925-850 MB... WILL BUMP LOWS UP JUST A BIT MAINLY ACROSS THE NORTH TO 64-70. FOR THURSDAY/THURSDAY NIGHT: THE FRONT IS EXPECTED TO SETTLE ALONG THE SRN BORDER OF NC THURSDAY. AN ELONGATED CANADIAN-SOURCE HIGH ATTEMPTS TO BUILD IN BEHIND THE FRONT FROM THE NW... HOWEVER THE COOLER AIR APPEARS TO BE HINDERED BY THE MOUNTAINS SUCH THAT LOW LEVEL THICKNESSES HOLD ABOVE NORMAL... AND A WEAK LEE TROUGH DEVELOPS OVER THE PIEDMONT IN THE AFTERNOON. THE COLUMN DRIES BACK OUT RATHER QUICKLY WITH NO INSTABILITY NOR LARGE SCALE LIFT... SO DON`T ANTICIPATE ANY PRECIP ALONG THE FRONTAL ZONE OR TROUGH ON THURSDAY... ALTHOUGH WE COULD SEE SOME MID OR HIGH LEVEL CLOUDINESS IN THE MORNING AS ANOTHER WEAK WAVE ALOFT DROPS THROUGH NC. HIGHS 87-93. LOWS 58-65 WITH A SECONDARY SURGE OF DRIER AIR DROPPING THROUGH THE STATE OVERNIGHT. -GIH && .LONG TERM /FRIDAY THROUGH MONDAY/... AS OF 235 PM MONDAY... FOR FRIDAY THROUGH SATURDAY: THE FRONT TO OUR SSW TRIES TO HEAD BACK NORTHEAST AS A WARM FRONT ON FRIDAY ACCORDING TO THE LATEST GFS/ECMWF. BUT AS THE MID LEVEL VORTEX SITS AND SPINS OVER NOVA SCOTIA WITH TROUGHING ENCOMPASSING MOST OF THE EASTERN SEABOARD AND WRN ATLANTIC... THE BLOCKING PATTERN SHOULD HELP KEEP THE SURFACE RIDGE DOMINANT THROUGH FRIDAY NIGHT. BUT THE ECMWF (AND TO A LESSER DEGREE THE GFS) INDICATES 850 MB NOCTURNAL JETTING NOSING INTO SWRN NC ALONG THE FRONT LATE FRIDAY INTO FRIDAY NIGHT... WHICH COULD INDUCE ENOUGH FORCING AND LOW LEVEL MOISTURE POOLING TO KICK OFF SLOW-MOVING SHOWERS OR STORMS. THE GFS/ECMWF BOTH SUGGEST THAT THIS MOISTURE IS ROOTED IN THE REMAINS OF NOW-TROPICAL STORM HERMINE... QUITE REASONABLE CONSIDERING THE MEAN FLOW PATTERN AND GOOD MODEL AGREEMENT. WILL SPREAD IN CHANCE POPS FROM SW TO E VERY LATE FRIDAY THROUGH FRIDAY NIGHT INTO SATURDAY MORNING. THE GFS/ECMWF ALSO BOTH SHOW A LOW FORMING AND TRACKING ALONG THE FRONT JUST TO OUR SOUTH... WHICH RESULTS IN AN ENHANCED NORTHEAST LOW LEVEL FLOW FRIDAY NIGHT INTO SATURDAY... POTENTIALLY RESULTING IN A WEAK IN SITU DAMMING EVENT. WHILE IT IS TOO FAR OFF WITH TOO MUCH UNCERTAINTY TO PUT MUCH FAITH IN SUCH A SCENARIO... IT WILL BE SOMETHING TO WATCH IN THE COMING DAYS. FOR NOW WILL TAPER POPS DOWN SATURDAY AFTERNOON BUT KEEP A GOOD BIT OF CLOUD COVER OVER THE AREA. WILL HAVE HIGHS NEAR NORMAL... 82-88... BUT CONFIDENCE IS BELOW NORMAL AND IF THE PRECIP COVERAGE IS GREATER THAN EXPECTED FRIDAY NIGHT/SATURDAY... HIGHS COULD BE BELOW NORMAL ON SATURDAY. LOWS IN THE 60S. FOR SATURDAY NIGHT THROUGH MONDAY: THE BLOCKING VORTEX OVER NOVA SCOTIA FINALLY WEAKENS AND GETS NUDGED EASTWARD BY A STRONG SHORTWAVE NOW APPROACHING THE PACIFIC NORTHWEST. THE MID LEVEL RIDGE BETWEEN THESE TWO FEATURES DEAMPLIFIES SO IT LOOKS LIKELY THAT BROAD TROUGHING WILL BECOME RE-ESTABLISHED OVER THE EASTERN US BY MONDAY. THE OPERATIONAL MODELS DIVERGE HOWEVER WITH THE ECMWF MUCH MORE AMPLIFIED THAN THE GFS... RESULTING IN THE ECMWF LEANING TOWARD KEEPING THE SURFACE FRONTAL ZONE JUST SOUTH OF THE CWA WITH COOLER TEMPS AND DRY WEATHER... WHILE THE GFS ALLOWS THE WARM SECTOR TO SURGE UP INTO THE CAROLINAS WITH MUCH WARMER TEMPS AND BETTER RAIN CHANCES. THE LESS AMPLIFIED GFS HAS SUPPORT FROM THE ECMWF ENSEMBLE MEAN AND THUS WAS PREFERRED. WILL HAVE LOW CHANCES OF AFTERNOON THROUGH EVENING SHOWERS/STORMS... WITH TEMPS GENERALLY A CATEGORY ABOVE NORMAL. -GIH && .AVIATION /18Z MONDAY THROUGH FRIDAY/... AS OF 127 PM MONDAY... CURRENTLY HIGH PRESSURE IS STILL DOMINATING THE WEATHER PATTERN OVER CENTRAL NC. SOME CONVECTION HAS BEGUN ASSOCIATED WITH A STATIONARY SURFACE FRONT LOCATED ALONG THE COAST WHERE IT IS EXPECTED TO REMAIN. NOT INCLUDING ANY MENTION OF PRECIPITATION AT ANY TAF SITE THIS AFTERNOON OR EVENING ALTHOUGH A ROGUE SHOWER COULD BE POSSIBLE IN THE SOUTH AND EAST. AT THIS HOUR VISIBLE SATELLITE DEPICTS SCATTERED CLOUDS IN THE 4-7 KFT RANGE ACROSS MUCH OF THE AREA. WINDS TODAY SHOULD REMAIN LIGHT AND VARIABLE AND DECREASE TO NEAR CALM OVERNIGHT. HAVE INCLUDED LOW STRATUS IN THE TAFS OVERNIGHT FOR KINT AND KGSO WITHOUT VISIBILITY RESTRICTIONS. UNEXPECTED STRATUS IN THE WEST EARLY THIS MORNING COUPLED WITH MORE FAVORABLE CONDITIONS OVERNIGHT YIELD MODERATELY HIGH CONFIDENCE THAT STRATUS WILL AGAIN FORM OVERNIGHT TONIGHT SOMEWHERE IN THE 1-2 KFT RANGE. BR AND FOG ARE MORE LIKELY FURTHER SOUTH AND EAST WITH MORE MOISTURE PRESENT ALONG THE COAST AND WINDS DYING OFF OVERNIGHT. FOR NOW WILL HAVE BR AT KRDU AND FOG FOG DOWN TO A HALF MILE AT KRWI AND KFAY. IFR CONDITIONS ARE LIKELY AT ALL OF THESE SITES WITH LIFR POSSIBLE ESPECIALLY IN THE EAST. ONSET OF THE FOG SHOULD BE FROM EAST TO WEST AND HAVE ADJUSTED THE TIMING IN THE TAFS TO REFLECT THIS. AFTER THE FOG AND STRATUS LIFT TOMORROW MORNING...EXPECTING VFR CONDITIONS THROUGHOUT THE DAY. WINDS WILL INCREASE SLIGHTLY TO 5-10 KNOTS AND CARRY A MORE DEFINED DIRECTION OUT OF THE SOUTH SOUTHWEST. LOOKING AHEAD THROUGH FRIDAY CONDITIONS SHOULD REMAIN VFR...BUT THE BEST CHANCE FOR MVFR/IFR CONDITIONS EXISTS WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF A WEAK FRONT. FOG AND/OR LOW STRATUS IS ALSO POSSIBLE OVERNIGHT TUESDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMITH NEAR TERM...SMITH SHORT TERM...HARTFIELD LONG TERM...HARTFIELD AVIATION...ELLIS 000 FXUS62 KRAH 061831 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 230 PM EDT MON SEP 6 2010 .SYNOPSIS... A DRY RIDGE OF HIGH PRESSURE WILL EXTEND ACROSS NC THROUGH TUESDAY. A WEAK COLD FRONT WILL CROSS THE AREA LATE WEDNESDAY. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD SOUTH INTO THE AREA FOR THE REMAINDER OF THE WEEK. && .NEAR TERM /THROUGH TUESDAY NIGHT/... AS OF 220 PM MONDAY... COVERAGE OF CU FIELD IS A LITTLE MORE EXTENSIVE THAN PREVIOUSLY FORECAST...BUT IT DOESN`T APPEAR TO BE HINDERING INSOLATION TOO MUCH TO STRAY FROM CURRENT HIGH TEMP FORECAST THIS AFTERNOON. HAVE ADJUSTED SKY COVER GRIDS TOWARD REALITY. HEIGHT RISES ALOFT WILL BEGIN THIS EVENING AS AN UPPER RIDGE BUILDS NE TOWARD THE MID ATLANTIC STATES...AHEAD OF A SHORTWAVE TROUGH LIFTING THROUGH THE NORTHERN PLAINS STATES. SURFACE HIGH PRESSURE OFF THE NJ COAST WILL CONTINUE TO RIDGE SW OVER THE CAROLINAS INTO TUESDAY....WITH WEAK WARM ADVECTION AND LIGHT EAST-SOUTHEASTERLY FLOW KICKING IN OVER THE CWA THIS EVENING. NAM CROSS-SECTIONS SUGGEST UPSLOPE FROM THE LOW LEVEL FLOW AROUND THE HIGH COMBINED WITH A DECENT WARM ADVECTION PROFILE WILL BE SUFFICIENT FOR STRATUS OVER THE WESTERN HALF OF THE CWA. DEWPOINTS WILL BE STARTING OUT RATHER LOW OVER A GOOD PORTION OF THE AREA...BUT A DECENT DEWPOINT RECOVERY ACROSS THE SOUTH WITH A SOUTHEASTERLY FETCH MAY LEAD TO SOME PATCHY FOG BY TUESDAY MORNING. LOWS A COUPLE DEGREES WARMER THAN THIS PAST MORNING...59-64. THE AFOREMENTIONED NORTHERN PLAINS SHORTWAVE AND ITS ASSOCIATED SURFACE LOW WILL DRIVE A COLD FRONT SE INTO THE OHIO VALLEY REGION ON TUESDAY. THE AIRMASS SHOULD MODERATE A BUT MORE WITH A DEVELOPING SOUTHWESTERLY FLOW AND 1000-850MB THICKNESSES PROGGED TO RISE INTO THE 1420-1425M RANGE. THICKNESS AND 850MB MIXING BOTH YIELD VALUES CONSISTENT WITH STATISTICAL GUIDANCE...88-92. CONTINUED WITH DRY FORECAST AS PW RECOVERY IS FORECAST TO BE RATHER WEAK DURING THE DAY TUESDAY AND MODELS ARE NOT SHOWING MUCH DEVELOPMENT OF A PREFRONTAL TROUGH WITH HIGH PRESSURE REMAINING DOMINANT. SHOULD SEE MAINLY CLEAR SKIES TUESDAY NIGHT WITH SOUTHWESTERLY FLOW AHEAD OF WHAT LOOKS TO BE A MAINLY DRY APPROACHING COLD FRONT. HAVE LOWS WARMER THAN GUIDANCE...65-67. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 215 AM MONDAY... WEDNESDAY AND WEDNESDAY NIGHT: CLOSED UPPER LOW IS EXPECTED TO CONTINUE TRACKING EASTWARD ACROSS SOUTHERN ONTARIO INTO SOUTHERN QUEBEC AND NEW ENGLAND ON WEDNESDAY INTO WEDNESDAY NIGHT ALLOWING THE MID/UPPER LEVEL RIDGE TO DAMPEN ACROSS OUR AREA. THIS WILL ALLOW A TRAILING COLD FRONT TO MOVE THROUGH CENTRAL NC WEDNESDAY EVENING INTO THURSDAY MORNING. GIVEN THE GENERALLY WESTERLY FLOW PRECEDING THE FRONT WOULD EXPECT LITTLE IF ANY PRECIP WITH THIS FRONT. HOWEVER... MODELS NOW SHOW PW`S INCREASING TO NEAR 1.7 INCHES ACROSS THE SOUTHERN HALF OF THE CWA JUST AHEAD OF THE FRONT. HOWEVER... WILL LEAVE MENTION OF PRECIP OUT FOR NOW AS MODELS DO NOT SHOW MUCH IN THE WAY...IF ANY...OF QPF. HIGH TEMPS ON WEDNESDAY LOOK TO BE IN THE LOWER TO MID 90S... DESPITE THE DAMPENING OF THE RIDGE AND MID AND HIGH LEVEL CLOUD COVERAGE INCREASING DURING THE AFTERNOON AHEAD OF THE FRONT. HOWEVER...LOW LEVEL THICKNESS VALUES INCREASE FROM TUESDAY AFTERNOON SOME 10 TO 15 METERS. THUS...LOWER TO MID 90S LOOK GOOD. EXPECT LOWS THURSDAY MORNING TO GENERALLY BE IN THE MID TO UPPER 60S...WITH PERHAPS SOME LOWER 60S ACROSS THE NORTH WHERE WE SHOULD BEGIN TO CLEAR OUT BY SUNRISE. THURSDAY AND THURSDAY NIGHT: HIGH PRESSURE AT THE SURFACE IS EXPECTED TO BUILD INTO THE AREA FROM THE NORTH DURING THIS TIME FRAME...AS 500 HPA HEIGHT BEGIN TO SLOWLY RECOVER AS RIDGING ACROSS THE CENTRAL U.S. SLOWLY TRANSLATES EASTWARD. THIS SHOULD LEAD TO A PLEASANT DAY ON THURSDAY AFTERNOON...WITH LOWER DEWPOINTS. WITH GENERALLY MOSTLY SUNNY SKIES EXPECT TEMPS TO TOP OUT IN THE UPPER 80S TO NEAR 90. DRY CONDITIONS ARE EXPECTED TO CONTINUE INTO THURSDAY NIGHT...WITH LOWS EXPECTED TO FALL INTO THE LOWER TO MID 60S. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 235 AM MONDAY... FRIDAY THROUGH SUNDAY: MEDIUM RANGE MODELS GENERALLY AGREE ON THE UPPER LEVEL PATTERN AT THE START OF THE MEDIUM RANGE (TROUGH ACROSS THE WESTERN U.S... RIDGE CENTRAL U.S... AND TROUGH ALONG THE EAST COAST). HOWEVER... AMPLIFICATION AND SUBSEQUENTLY THE PROGRESSION OF THE PATTERN (GFS FASTER... ECMWF SLOWER) ARE IN QUESTION. THIS WILL NO DOUBT AFFECT THE FORECAST FOR LATE NEXT WEEK INTO THE WEEKEND. ALL MEDIUM RANGE GUIDANCE DEPICTS REMNANTS FROM A TROPICAL SYSTEM CURRENTLY LOCATED ACROSS PORTIONS OF THE WESTERN GULF OF MEXICO... TRACKING AROUND THE CENTER OF THE MID LEVEL RIDGE (THE DEEP SOUTH) AND ACROSS THE MID ATLANTIC OR SOUTHEAST BY FRIDAY NIGHT INTO SATURDAY. HOWEVER... PLACEMENT AND TIMING OF THIS FEATURE ARE STILL IN QUESTION. FOR NOW WILL CONTINUE A DRY FORECAST FOR FRIDAY AND ADD ONLY A SLIGHT CHANCE OF SHOWERS FOR SATURDAY. HOWEVER... POPS MAY BE NEED TO ADDED FOR FRIDAY NIGHT AND INCREASED ON SATURDAY AS WELL IN LATER SHIFT WHEN MODELS BEGIN TO CONVERGE ON A SOLUTION. FOR SUNDAY... MODELS CONTINUE TO INDICATE THE POTENTIAL FOR ANOTHER FRONT MAKING IT INTO/APPROACHING THE AREA EITHER NEXT SUNDAY OR EARLY NEXT WEEK. HOWEVER... WILL THE LEAVE THE FORECAST DRY FOR SUNDAY... GIVEN THE UNCERTAINTY AND TIMING DIFFERENCES. HIGHS DURING THIS TIME ARE EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 AND LOWS IN THE MID TO UPPER 60S. && .AVIATION /18Z MONDAY THROUGH FRIDAY/... AS OF 127 PM MONDAY... CURRENTLY HIGH PRESSURE IS STILL DOMINATING THE WEATHER PATTERN OVER CENTRAL NC. SOME CONVECTION HAS BEGUN ASSOCIATED WITH A STATIONARY SURFACE FRONT LOCATED ALONG THE COAST WHERE IT IS EXPECTED TO REMAIN. NOT INCLUDING ANY MENTION OF PRECIPITATION AT ANY TAF SITE THIS AFTERNOON OR EVENING ALTHOUGH A ROGUE SHOWER COULD BE POSSIBLE IN THE SOUTH AND EAST. AT THIS HOUR VISIBLE SATELLITE DEPICTS SCATTERED CLOUDS IN THE 4-7 KFT RANGE ACROSS MUCH OF THE AREA. WINDS TODAY SHOULD REMAIN LIGHT AND VARIABLE AND DECREASE TO NEAR CALM OVERNIGHT. HAVE INCLUDED LOW STRATUS IN THE TAFS OVERNIGHT FOR KINT AND KGSO WITHOUT VISIBILITY RESTRICTIONS. UNEXPECTED STRATUS IN THE WEST EARLY THIS MORNING COUPLED WITH MORE FAVORABLE CONDITIONS OVERNIGHT YIELD MODERATELY HIGH CONFIDENCE THAT STRATUS WILL AGAIN FORM OVERNIGHT TONIGHT SOMEWHERE IN THE 1-2 KFT RANGE. BR AND FOG ARE MORE LIKELY FURTHER SOUTH AND EAST WITH MORE MOISTURE PRESENT ALONG THE COAST AND WINDS DYING OFF OVERNIGHT. FOR NOW WILL HAVE BR AT KRDU AND FOG FOG DOWN TO A HALF MILE AT KRWI AND KFAY. IFR CONDITIONS ARE LIKELY AT ALL OF THESE SITES WITH LIFR POSSIBLE ESPECIALLY IN THE EAST. ONSET OF THE FOG SHOULD BE FROM EAST TO WEST AND HAVE ADJUSTED THE TIMING IN THE TAFS TO REFLECT THIS. AFTER THE FOG AND STRATUS LIFT TOMORROW MORNING...EXPECTING VFR CONDITIONS THROUGHOUT THE DAY. WINDS WILL INCREASE SLIGHTLY TO 5-10 KNOTS AND CARRY A MORE DEFINED DIRECTION OUT OF THE SOUTH SOUTHWEST. LOOKING AHEAD THROUGH FRIDAY CONDITIONS SHOULD REMAIN VFR...BUT THE BEST CHANCE FOR MVFR/IFR CONDITIONS EXISTS WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF A WEAK FRONT. FOG AND/OR LOW STRATUS IS ALSO POSSIBLE OVERNIGHT TUESDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...SMITH NEAR TERM...SMITH SHORT TERM...BSD LONG TERM...BSD AVIATION...ELLIS 000 FXUS62 KMHX 061816 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 216 PM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE TO THE NORTHEAST WILL CONTINUE TO EXTEND SOUTHWEST INTO THE REGION THROUGH TUESDAY NIGHT. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY AND SLIDE OFFSHORE SATURDAY. A COLD FRONT WILL SLOWLY APPROACH FROM THE NORTHWEST SUNDAY AND MOVE INTO THE AREA MONDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 2 PM MON...AREA OF SHRA AND TSRA CONTS WELL TO THE S AND EXPECT THIS TO DRIFT AWAY/DISSIPATE INTO THE EVENING AS SRT WAVE NEAR THE CST MOVES FURTHER E. HIGH PRES TO THE NE WILL EXTEND SW INTO THE REGION WITH MCLR SKIES...LOWS WILL RANGE FROM 60 TO 65 INLAND TO AROUND 70 BEACHES. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 2 PM MON...CONT DRY TUE AND WED AS SFC HIGHS CONTS TO EXTEND SW INTO THE AREA WITH RDG ALOFT JUST TO THE S. HIGHS TUE WILL REACH UPR 80S INLAND WITH AROUND 90 WED AS FLOW GOES SW AHEAD OF APPROACHING COLD FRONT. FRONT WILL DROP SE THROUGH THE AREA WED NIGHT. GFS CONT TO BE WETTEST MODEL WITH SOME QPF MAINLY CST. NAM AND ECMWF ARE DRIER...FOR NOW ADDED SLIGHT POP CNTRL AND SRN CSTL WTRS FOR THE FROPA LATER WED NIGHT. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 2 PM MON...COLD FRONT WILL STALL TO THE S THU WITH HIGH PRES TO THE N. EXPECT DRY WX THU AND FRI WITH TEMPS MAINLY MID/UPR 80S. GFS SHOWS REMNANTS OF HERMINE MAKING IT TO OH VLY REGION LATE FRI BEFORE MERGING WITH DEVELOPING ERN TRF AND CROSSING THE REGION SAT. ECMWF IS MORE ROBUST WITH THE REMNANTS SHOWING A WELL DEFINED VORT MAX AND ASSOC PRECIP BULLS EYE MOVING ACROSS SAT. WILL LEAN MORE TOWARD GFS BUT DO EXPECT BETTER MOISTURE WILL LEAD TO SCT CONVECTION SAT. SRT WAVES CROSSING IN ZONAL FLOW WILL LEAD TO CONT CHC POPS SUN INTO MON AS COLD FRONT SAGS S INTO THE AREA. HIGHS MAINLY MID TO UPR 80S INLAND WITH LOW TO MID 80S CST THRU THE PERIOD. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 2 PM MON...HIGH PRESSURE CURRENTLY IN CONTROL OVER MUCH OF THE MID- ATLANTIC REGION WILL GIVE WAY TO MAINLY CLEAR SKIES THROUGHOUT THE TAF PERIOD. HOWEVER...A STALLED FRONT OFFSHORE WILL ALLOW SOME LINGERING CLOUDS (BASES ~8KFT) TO MIGRATE INTO THE REGION...CONFINED NEAR THE COAST. WINDS WILL VEER THROUGHOUT THE DAY FROM NE TO SE AROUND 8KTS WITH THE OCCASIONAL GUST. WITH LIGHT WINDS AND CLEAR SKIES OVERNIGHT...ANTICIPATE SOME PATCHY FOG TO DEVELOP BETWEEN 06-12Z TUESDAY. ANY LOW LEVEL MOISTURE IN PLACE EARLY TUESDAY WILL QUICKLY DISSIPATE AFTER SUNRISE AS BOUNDARY LAYER MIXING INCREASES. SIMILAR TO TODAY...EXPECT CLEAR SKIES AND WINDS VEERING NE TO SE AROUND 5-8KTS TUESDAY. BEYOND 18Z TUESDAY...A FRONT WILL APPROACH THE REGION WEDNESDAY INTO THURSDAY. CLOUD COVER AND SW WINDS WILL BE ON THE INCREASE WEDNESDAY AFTERNOON AHEAD OF THE BOUNDARY. THE BEST CHANCE OF ANY PRECIPITATION WILL BE WEDNESDAY NIGHT INTO EARLY THURSDAY. HIGH PRESSURE WILL BUILD INTO THE REGION LATE THURSDAY BEFORE THE NEXT SYSTEM APPROACHES THIS WEEKEND. && .MARINE... AS OF 2 PM MON...12Z GFS/NAM IN FAIRLY GOOD AGREEMENT THROUGH THE PERIOD...WITH THE NAM WIND SPEEDS BEING A BIT HIGHER THAN THE GFS. COMPARING CURRENT WIND SPEEDS ACROSS THE MARINE AREA IT APPEARS THE STRONGER NAM IS PREFERRED SO WILL USE IT FOR THE AFTERNOON PACKAGE. WAVY STATIONARY FRONT OFF THE SOUTHEAST COAST WILL GRADUALLY DISSIPATE. SW-NE ORIENTED SURFACE RIDGE TO OUR NW WILL SETTLE INTO THE AREA TUESDAY WITH LIGHT WINDS OF 5-10 KNOTS...AS COMPARED TO 10-20 KNOTS THIS AFTERNOON. WINDS WILL INCREASE AGAIN WEDNESDAY AND WEDNESDAY NIGHT AHEAD OF APPROACHING COLD FRONT. THE FRONT WILL MOVE OFF THE SOUTH COAST THURSDAY MORNING WITH WINDS BECOMING NORTH. LIGHT WINDS AND SEAS EXPECTED IN THE WAKE OF THE FRONT INTO THE WEEKEND WITH HIGH PRESSURE PASSING FAR TO THE NORTH. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...RF NEAR TERM...RF SHORT TERM...RF LONG TERM...RF AVIATION...LP MARINE...HSA 000 FXUS62 KRAH 061726 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 0127 PM EDT MON SEP 6 2010 .SYNOPSIS... A DRY HIGH PRESSURE RIDGE WILL EXTEND ACROSS NC THROUGH THE MIDDLE OF THE WEEK. A WEAK COLD FRONT WILL THEN DRIFT ACROSS THE STATE WEDNESDAY NIGHT. && .NEAR TERM /TODAY THROUGH TUESDAY NIGHT/... AS OF 950 AM MONDAY... CHANGES TO THE FORECAST ARE VERY MINOR THIS MORNING. THE AXIS OF A SHORTWAVE TROUGH IS CROSSING THE AREA THIS MORNING...WITH BROAD HEIGHT RISES ALOFT BEHIND THE TROUGH FROM THE EASTERN GREAT LAKES TO THE TENNESSEE VALLEY. SURFACE HIGH PRESSURE LOCATED NEAR THE MASON-DIXON LINE IS FORECAST TO SLIDE OFFSHORE TODAY...WITH WEAK WARM ADVECTION AND LIGHT EAST-SOUTHEASTERLY FLOW KICKING IN OVER THE CWA. PWS CONTINUE TO BE LOW THIS MORNING...WITH 0.83" OBSERVED AT KGSO AT 12Z. WILL SEE SOME PATCHY FLAT CU WHERE MORNING STRATUS FROM LEXINGTON TO SANFORD HAS LIFTED TO 5-7K FT...AND ALSO OVER THE SOUTHERN COASTAL PLAIN AS SOME COASTAL MOISTURE ADVECTS INLAND. OTHERWISE EXPECT MOSTLY SUNNY SKIES. THE 06Z NAM VERIFIED BEST WITH 850MB TEMPS THIS MORNING....AND WITH FORECAST SOUNDINGS SHOWING MIXING UP TO 800MB...HAVE NUDGED HIGHS TOWARD THE NAM WITH 86-90 NE-SW. -SMITH LOW TEMPS TUE WILL BE AT LEAST SEVERAL DEGREES WARMER THAN THIS MORNING DUE TO AIRMASS MODIFICATION/RISING THICKNESSES...IN THE UPPER 50S TO LOWER 60S. TUESDAY AND TUESDAY NIGHT: THE H5 RIDGE WILL PEAK IN STRENGTH OVER THE SOUTHEAST STATES/ CAROLINAS ON TUE BEFORE WEAKENING AND FLATTENING OUT TUE NIGHT AND WED AS A POTENT H5 LOW MOVES EAST ACROSS THE GREAT LAKES INTO NEW ENGLAND. RELATIVELY STRONG 1024 MB SFC HIGH PRESSURE OFFSHORE THE MID-ATLANTIC (AND EXTENDING SW INTO THE CAROLINAS) IS PROGGED TO WEAKEN TUE AS A PRE-FRONTAL TROUGH APPROACHES FROM THE WEST...WITH THE PRE-FRONTAL TROUGH OVER CENTRAL NC BY 12Z WED. FCST SOUNDINGS ARE CONSISTENT WITH SYNOPTIC SUBSIDENCE DURING THE DAY TUE...WITH WARM/DRY MID-LEVELS AND BELOW NORMAL PWAT VALUES AT OR BELOW 1". AS A RESULT...THE FORECAST WILL REMAIN DRY WITH SUNNY SKIES (ASIDE FROM PERHAPS A FEW FLAT DIURNAL CU) AND NO CHANCE FOR PRECIPITATION. THE PRE-FRONTAL TROUGH WILL ALLOW FOR SOME LOW LEVEL CONVERGENCE AND MOISTENING WHEN IT MOVES INTO THE AREA TUE NIGHT...HOWEVER...UPPER LEVEL FORCING WILL BE ABSENT...AND THE LOW-LEVEL FORCING/MOISTURE WILL BE INADEQUATE TO SUPPORT ANT PRECIPITATION. WILL CONTINUE A DRY FCST TUE NIGHT...WITH PARTLY TO MOSTLY CLOUDY SKIES PRIMARILY ASSOC/W UPPER LEVEL CLOUD COVER MOVING INTO THE AREA VIA WESTERLY FLOW ALOFT. 1000-850 MB THICKNESSES FURTHER INCREASE TO 1415-1420 METERS UNDER THE STRENGTHENING H5 RIDGE TUE...INDICATING HIGH TEMPS A FEW DEGREES WARMER THAN TODAY...IN THE UPPER 80S TO LOWER 90S. LOWS TUE NIGHT WILL BE TEMPERED SOMEWHAT BY INCREASING UPPER LEVEL CLOUD COVER AND WEAK WARM ADVECTION. WILL FCST LOWS IN THE LOWER/MID 60S...CLOSE TO MOS GUIDANCE. -VINCENT && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 215 AM MONDAY... WEDNESDAY AND WEDNESDAY NIGHT: CLOSED UPPER LOW IS EXPECTED TO CONTINUE TRACKING EASTWARD ACROSS SOUTHERN ONTARIO INTO SOUTHERN QUEBEC AND NEW ENGLAND ON WEDNESDAY INTO WEDNESDAY NIGHT ALLOWING THE MID/UPPER LEVEL RIDGE TO DAMPEN ACROSS OUR AREA. THIS WILL ALLOW A TRAILING COLD FRONT TO MOVE THROUGH CENTRAL NC WEDNESDAY EVENING INTO THURSDAY MORNING. GIVEN THE GENERALLY WESTERLY FLOW PRECEDING THE FRONT WOULD EXPECT LITTLE IF ANY PRECIP WITH THIS FRONT. HOWEVER... MODELS NOW SHOW PW`S INCREASING TO NEAR 1.7 INCHES ACROSS THE SOUTHERN HALF OF THE CWA JUST AHEAD OF THE FRONT. HOWEVER... WILL LEAVE MENTION OF PRECIP OUT FOR NOW AS MODELS DO NOT SHOW MUCH IN THE WAY...IF ANY...OF QPF. HIGH TEMPS ON WEDNESDAY LOOK TO BE IN THE LOWER TO MID 90S... DESPITE THE DAMPENING OF THE RIDGE AND MID AND HIGH LEVEL CLOUD COVERAGE INCREASING DURING THE AFTERNOON AHEAD OF THE FRONT. HOWEVER...LOW LEVEL THICKNESS VALUES INCREASE FROM TUESDAY AFTERNOON SOME 10 TO 15 METERS. THUS...LOWER TO MID 90S LOOK GOOD. EXPECT LOWS THURSDAY MORNING TO GENERALLY BE IN THE MID TO UPPER 60S...WITH PERHAPS SOME LOWER 60S ACROSS THE NORTH WHERE WE SHOULD BEGIN TO CLEAR OUT BY SUNRISE. THURSDAY AND THURSDAY NIGHT: HIGH PRESSURE AT THE SURFACE IS EXPECTED TO BUILD INTO THE AREA FROM THE NORTH DURING THIS TIME FRAME...AS 500 HPA HEIGHT BEGIN TO SLOWLY RECOVER AS RIDGING ACROSS THE CENTRAL U.S. SLOWLY TRANSLATES EASTWARD. THIS SHOULD LEAD TO A PLEASANT DAY ON THURSDAY AFTERNOON...WITH LOWER DEWPOINTS. WITH GENERALLY MOSTLY SUNNY SKIES EXPECT TEMPS TO TOP OUT IN THE UPPER 80S TO NEAR 90. DRY CONDITIONS ARE EXPECTED TO CONTINUE INTO THURSDAY NIGHT...WITH LOWS EXPECTED TO FALL INTO THE LOWER TO MID 60S. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 235 AM MONDAY... FRIDAY THROUGH SUNDAY: MEDIUM RANGE MODELS GENERALLY AGREE ON THE UPPER LEVEL PATTERN AT THE START OF THE MEDIUM RANGE (TROUGH ACROSS THE WESTERN U.S... RIDGE CENTRAL U.S... AND TROUGH ALONG THE EAST COAST). HOWEVER... AMPLIFICATION AND SUBSEQUENTLY THE PROGRESSION OF THE PATTERN (GFS FASTER... ECMWF SLOWER) ARE IN QUESTION. THIS WILL NO DOUBT AFFECT THE FORECAST FOR LATE NEXT WEEK INTO THE WEEKEND. ALL MEDIUM RANGE GUIDANCE DEPICTS REMNANTS FROM A TROPICAL SYSTEM CURRENTLY LOCATED ACROSS PORTIONS OF THE WESTERN GULF OF MEXICO... TRACKING AROUND THE CENTER OF THE MID LEVEL RIDGE (THE DEEP SOUTH) AND ACROSS THE MID ATLANTIC OR SOUTHEAST BY FRIDAY NIGHT INTO SATURDAY. HOWEVER... PLACEMENT AND TIMING OF THIS FEATURE ARE STILL IN QUESTION. FOR NOW WILL CONTINUE A DRY FORECAST FOR FRIDAY AND ADD ONLY A SLIGHT CHANCE OF SHOWERS FOR SATURDAY. HOWEVER... POPS MAY BE NEED TO ADDED FOR FRIDAY NIGHT AND INCREASED ON SATURDAY AS WELL IN LATER SHIFT WHEN MODELS BEGIN TO CONVERGE ON A SOLUTION. FOR SUNDAY... MODELS CONTINUE TO INDICATE THE POTENTIAL FOR ANOTHER FRONT MAKING IT INTO/APPROACHING THE AREA EITHER NEXT SUNDAY OR EARLY NEXT WEEK. HOWEVER... WILL THE LEAVE THE FORECAST DRY FOR SUNDAY... GIVEN THE UNCERTAINTY AND TIMING DIFFERENCES. HIGHS DURING THIS TIME ARE EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 AND LOWS IN THE MID TO UPPER 60S. && .AVIATION /18Z MONDAY THROUGH FRIDAY/... AS OF 127 PM MONDAY... CURRENTLY HIGH PRESSURE IS STILL DOMINATING THE WEATHER PATTERN OVER CENTRAL NC. SOME CONVECTION HAS BEGUN ASSOCIATED WITH A STATIONARY SURFACE FRONT LOCATED ALONG THE COAST WHERE IT IS EXPECTED TO REMAIN. NOT INCLUDING ANY MENTION OF PRECIPITATION AT ANY TAF SITE THIS AFTERNOON OR EVENING ALTHOUGH A ROGUE SHOWER COULD BE POSSIBLE IN THE SOUTH AND EAST. AT THIS HOUR VISIBLE SATELLITE DEPICTS SCATTERED CLOUDS IN THE 4-7 KFT RANGE ACROSS MUCH OF THE AREA. WINDS TODAY SHOULD REMAIN LIGHT AND VARIABLE AND DECREASE TO NEAR CALM OVERNIGHT. HAVE INCLUDED LOW STRATUS IN THE TAFS OVERNIGHT FOR KINT AND KGSO WITHOUT VISIBILITY RESTRICTIONS. UNEXPECTED STRATUS IN THE WEST EARLY THIS MORNING COUPLED WITH MORE FAVORABLE CONDITIONS OVERNIGHT YIELD MODERATELY HIGH CONFIDENCE THAT STRATUS WILL AGAIN FORM OVERNIGHT TONIGHT SOMEWHERE IN THE 1-2 KFT RANGE. BR AND FOG ARE MORE LIKELY FURTHER SOUTH AND EAST WITH MORE MOISTURE PRESENT ALONG THE COAST AND WINDS DYING OFF OVERNIGHT. FOR NOW WILL HAVE BR AT KRDU AND FOG FOG DOWN TO A HALF MILE AT KRWI AND KFAY. IFR CONDITIONS ARE LIKELY AT ALL OF THESE SITES WITH LIFR POSSIBLE ESPECIALLY IN THE EAST. ONSET OF THE FOG SHOULD BE FROM EAST TO WEST AND HAVE ADJUSTED THE TIMING IN THE TAFS TO REFLECT THIS. AFTER THE FOG AND STRATUS LIFT TOMORROW MORNING...EXPECTING VFR CONDITIONS THROUGHOUT THE DAY. WINDS WILL INCREASE SLIGHTLY TO 5-10 KNOTS AND CARRY A MORE DEFINED DIRECTION OUT OF THE SOUTH SOUTHWEST. LOOKING AHEAD THROUGH FRIDAY CONDITIONS SHOULD REMAIN VFR...BUT THE BEST CHANCE FOR MVFR/IFR CONDITIONS EXISTS WEDNESDAY NIGHT INTO THURSDAY MORNING WITH THE PASSAGE OF A WEAK FRONT. FOG AND/OR LOW STRATUS IS ALSO POSSIBLE OVERNIGHT TUESDAY NIGHT. && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT/SMITH SHORT TERM...BSD LONG TERM...BSD AVIATION...ELLIS 000 FXUS62 KILM 061724 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 125 PM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE THROUGH WEDNESDAY. A WEAK FRONT WILL MOVE ACROSS THE AREA THURSDAY WITH LITTLE IMPACT ON THE WEATHER. A SLIGHT CHANCE OF SHOWERS WILL ENTER THE PICTURE NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM MONDAY...WAVE ALONG OLD FRONT LOCATED JUST OFF SHORE PUSHING MOISTURE TOWARD COASTAL SOUTH CAROLINA. SHARP MOISTURE GRADIENT EXISTED EARLY THIS MORNING WITH RUC SHOWING CLOSE TO 1.75 INCHES OF PCP WATER LOCATED ALONG SC COAST AND OVER COASTAL WATERS SOUTH OF CAPE FEAR BUT LESS THAN AN INCH OVER INLAND COUNTIES. WATER VAPOR IMAGERY SHOWING THIS MOISTURE GRADIENT VERY NICELY ALIGNED ALONG THE SOUTH CAROLINA COAST. SHORTWAVE RIDING ACROSS THE AREA HELPED TO TRIGGER SOME ISOLD SHWRS/TSTMS IN THIS MOISTURE RICH AIR. THIS MOISTURE BOUNDARY SHOULD GET PUSHED FARTHER OFF SHORE WITH PCP WATER VALUES DROPPING DOWN TO LESS THAN 1.25 INCHES ALONG TO THE COAST THIS AFTN. THEREFORE EXPECT SHWRS/TSTM ACTIVITY TO DECREASE OVER LOCAL AREA THIS AFTN AND RELOCATE FARTHER OFF SHORE IN THE COASTAL WATERS. SHOULD SEE SHWRS OVER LAND WITH TSTMS MAINLY CONFINED TO COASTAL WATERS THROUGH EARLY THIS AFTN AND BECOMING MORE ISOLD OVER LAND AREAS THROUGH THE DAY AS SHORTWAVE EXITS THE AREA AND RIDGE BUILDS ALOFT LATER TODAY THROUGH TUES MORNING. TEMPERATURES VERY SIMILAR TO YESTERDAY WITH LITTLE CHANGE IN THE THERMAL RIDGE OR OVERALL FLOW. MID 80S ALONG THE COAST TO UPPER 80S INLAND FOR HIGHS...MID 60S FOR LOWS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3:00 AM MONDAY...MASSIVE RIDGE WILL DOMINATE THROUGH MUCH OF THE PERIOD WITH HIGH PRESSURE EXTENDING OFF TO THE NORTHEAST AT THE SURFACE. RIDGE GETS SUPPRESSED TO THE SOUTH LATER WEDNESDAY AS A STRONG SHORTWAVE MOVES ACROSS THE GREAT LAKES. THIS ALLOWS A SURFACE FRONT TO MOVE ACROSS THE AREA BY THURSDAY MORNING. THE GFS AND ECMWF ARE DRY WITH THE NAM ADVERTISING SOME LIGHT QPF VIA SHALLOW FRONTAL FORCING. DID TREND UP POPS A BIT TO ADDRESS THIS POSSIBILITY WHILE REMAINING BELOW THE 15 PERCENT THRESHOLD WHICH WARRANTS MENTION IN THE ZONES. VERIFICATION NUMBERS OVER THE PAST 30 DAYS SHOW THE BIAS CORRECTED ADJUSTED MET NUMBERS ARE THE BEST OPTION REGARDING TEMPERATURES THROUGH THE PERIOD. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3:00 AM MONDAY...MEDIUM RANGE MODELS HAVE REVERTED BACK TO A LESS AMPLIFIED SOLUTION FOR THE END OF THE PERIOD AS THE MASSIVE RIDGE BUILDS BACK TO THE NORTHEAST. THE OPERATIONAL ECMWF CONTINUES TO ADVERTISE SLIGHTLY MORE AMPLITUDE WHEN COMPARED TO THE GFS BUT THIS SEEMS TO BE A RESULT OF FEEDBACK COURTESY OF THE REMAINING VORTICITY FROM TD TEN THAT MAKES IT ALL THE WAY TO THE ATLANTIC. AT THE SURFACE...AN OLD BOUNDARY WILL MOVE BACK WELL TO THE NORTH OF THE AREA LATER SATURDAY AND SUNDAY. PRECIPITABLE WATERS INCREASE TO OVER TWO INCHES AS A WEAK BERMUDA HIGH BUILDS IN AT THE SURFACE. FORCING WILL BE NEGLIGIBLE BUT HAVE INTRODUCED POPS FOR SATURDAY AND SUNDAY WITH THE MORNING UPDATE. NO CHANGES TO TEMPERATURE FORECAST WHICH CONTINUES ABOVE CLIMATOLOGY. && .AVIATION /18Z MONDAY THROUGH FRIDAY/... AS OF 18Z...WATER VAPOR IMAGERY CONTINUES TO SHOW VERY DRY AIR JUST INLAND OF THE IMMEDIATE COAST. SHOWERS ARE OCCURRING TO THE SOUTHWEST AND SOUTH OF MYR...WITH ISOLATED THUNDERSTORMS IN THE COASTAL WATERS WELL EAST AND SOUTHEAST OF THE MYR/CRE TERMINALS. HIGH CONFIDENCE VFR FORECAST FOR ALL TERMINALS THROUGH THIS EVENING. EAST TO SOUTHEAST WINDS AT 8-15 KNOTS...HIGHEST AT THE COASTAL TERMINALS WILL CONTINUE THROUGH THE AFTERNOON. MODELS ARE DEPICTING THE DEEPEST MOISTURE WILL REMAIN EAST OF THE TERMINALS THIS AFTERNOON...AND BELIEVE THIS IS WHERE THE BEST THUNDERSTORM POTENTIAL WILL REMAIN. BUT EASTERLY WINDS IN THE LOW LEVELS IS CONTINUING TO ADVECT LOW LEVEL MOISTURE INLAND. THIS ALONG WITH A RESULTANT BOUNDARY SHOULD COMBINE TO ALLOW SHOWERS TO DEVELOP THROUGH THE AFTERNOON...MOST LIKELY JUST INLAND OF MYR/CRE. LIMITED INSTABILITY...DRY AIR...WEAK CAPPING AND LACK OF LARGE SCALE LIFT SHOULD KEEP ACTIVITY ISOLATED AND NEGATE ANY THUNDERSTORM DEVELOPMENT INLAND AREAS. SOME OF THE SHOWERS COULD APPROACH THE FLO TERMINAL BY LATE AFTERNOON AS THE BOUNDARY MOVES FURTHER INLAND. BUT THE AIRMASS WILL BE BECOMING INCREASINGLY STABLE AS THE AFTERNOON PROGRESSES...SO EXPECTED SHOWER ACTIVITY TO DISSIPATE BEFORE REACHING THE FLO TERMINAL LATE AFTERNOON/SUNSET. BY SUNSET WINDS SHOULD BECOME LIGHT AND VARIABLE AT FLO/LBT AND AT THE COASTAL TERMINALS BY 02-03Z. TIME HEIGHT IMAGES SUGGEST A POSSIBILITY OF MVFR CEILINGS 1-2K DEVELOPING AFTER MIDNIGHT. THERE IS LOW CONFIDENCE OF OCCURRENCE ATTM. FOG DEVELOPMENT SEEMS MORE LIKELY WITH MODERATE CONFIDENCE THAT MVFR VISIBILITIES WILL DEVELOP. IFR VISIBILITIES COULD DEVELOP AT THE FLO/LBT TERMINALS...BUT CONFIDENCE IS LOW ATTM. BUT IF A SHOWER OCCURS AT THE FLO TERMINAL THIS AFTERNOON THEN IFR POTENTIAL WILL BECOME MORE LIKELY. WILL INDICATE MVFR VISIBILITIES DEVELOPING AT ALL TERMINALS AFTER MIDNIGHT. VFR EXPECTED TUESDAY MORNING AFTER SUNRISE WITH NORTHEAST TO EAST WINDS AROUND 5 KNOTS BECOMING EAST TO SOUTHEAST AT 10-15 KNOTS BY MID MORNING. EXTENDED OUTLOOK...LOW CONFIDENCE IFR VISIBILITIES DUE TO EARLY MORNING FOG EACH MORNING AT FLO/LBT. OTHERWISE...NO SIG WX EXPECTED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM MONDAY...LIGHT ON SHORE NE-E FLOW WILL EXIST AROUND HIGH PRESSURE CENTERED TO NORTH OF COASTAL WATERS. SEAS WILL BE 3 FT OR LESS OVER MOST WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3:00 AM MONDAY...WEAK GRADIENT INITIALLY WILL INCREASE LATER WEDNESDAY AS WINDS INCREASE FROM AROUND 10 KNOTS OR LESS TO AROUND 15 KNOTS FROM THE SOUTHWEST LATER WEDNESDAY. THIS INCREASE COURTESY OF AN APPROACHING FRONT. FRONT MOVES ACROSS BY THURSDAY MORNING WITH THE FLOW VEERING TO NW AND REMAINING LIGHT. WAVEWATCH SEAS REMAIN CONSISTENT AROUND 1-2 FEET. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3:00 AM MONDAY...NW WINDS INITIALLY WILL VEER TO NE BY THE END OF THE PERIOD AS HIGH PRESSURE...CENTERED OVER THE MID ATLANTIC GRUDGINGLY HANGS ON. GRADIENT IS WEAK HOWEVER AND WIND SPEEDS WILL REMAIN BELOW 10 KNOTS. WITH LITTLE TROPICAL ACTIVITY IN THE OPEN ATLANTIC...SIGNIFICANT WAVE HEIGHTS WILL REMAIN LOW IN A 2-3 FOOT RANGE WITH THE SPECTRUM ALMOST EXCLUSIVELY WIND WAVES. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...RGZ SHORT TERM...SHK LONG TERM...SHK AVIATION...MRR 000 FXUS62 KILM 061519 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 1119 AM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE THROUGH WEDNESDAY. A WEAK FRONT WILL MOVE ACROSS THE AREA THURSDAY WITH LITTLE IMPACT ON THE WEATHER. A SLIGHT CHANCE OF SHOWERS WILL ENTER THE PICTURE NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM MONDAY...WAVE ALONG OLD FRONT LOCATED JUST OFF SHORE PUSHING MOISTURE TOWARD COASTAL SOUTH CAROLINA. SHARP MOISTURE GRADIENT EXISTED EARLY THIS MORNING WITH RUC SHOWING CLOSE TO 1.75 INCHES OF PCP WATER LOCATED ALONG SC COAST AND OVER COASTAL WATERS SOUTH OF CAPE FEAR BUT LESS THAN AN INCH OVER INLAND COUNTIES. WATER VAPOR IMAGERY SHOWING THIS MOISTURE GRADIENT VERY NICELY ALIGNED ALONG THE SOUTH CAROLINA COAST. SHORTWAVE RIDING ACROSS THE AREA HELPED TO TRIGGER SOME ISOLD SHWRS/TSTMS IN THIS MOISTURE RICH AIR. THIS MOISTURE BOUNDARY SHOULD GET PUSHED FARTHER OFF SHORE WITH PCP WATER VALUES DROPPING DOWN TO LESS THAN 1.25 INCHES ALONG TO THE COAST THIS AFTN. THEREFORE EXPECT SHWRS/TSTM ACTIVITY TO DECREASE OVER LOCAL AREA THIS AFTN AND RELOCATE FARTHER OFF SHORE IN THE COASTAL WATERS. SHOULD SEE SHWRS OVER LAND WITH TSTMS MAINLY CONFINED TO COASTAL WATERS THROUGH EARLY THIS AFTN AND BECOMING MORE ISOLD OVER LAND AREAS THROUGH THE DAY AS SHORTWAVE EXITS THE AREA AND RIDGE BUILDS ALOFT LATER TODAY THROUGH TUES MORNING. TEMPERATURES VERY SIMILAR TO YESTERDAY WITH LITTLE CHANGE IN THE THERMAL RIDGE OR OVERALL FLOW. MID 80S ALONG THE COAST TO UPPER 80S INLAND FOR HIGHS...MID 60S FOR LOWS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3:00 AM MONDAY...MASSIVE RIDGE WILL DOMINATE THROUGH MUCH OF THE PERIOD WITH HIGH PRESSURE EXTENDING OFF TO THE NORTHEAST AT THE SURFACE. RIDGE GETS SUPPRESSED TO THE SOUTH LATER WEDNESDAY AS A STRONG SHORTWAVE MOVES ACROSS THE GREAT LAKES. THIS ALLOWS A SURFACE FRONT TO MOVE ACROSS THE AREA BY THURSDAY MORNING. THE GFS AND ECMWF ARE DRY WITH THE NAM ADVERTISING SOME LIGHT QPF VIA SHALLOW FRONTAL FORCING. DID TREND UP POPS A BIT TO ADDRESS THIS POSSIBILITY WHILE REMAINING BELOW THE 15 PERCENT THRESHOLD WHICH WARRANTS MENTION IN THE ZONES. VERIFICATION NUMBERS OVER THE PAST 30 DAYS SHOW THE BIAS CORRECTED ADJUSTED MET NUMBERS ARE THE BEST OPTION REGARDING TEMPERATURES THROUGH THE PERIOD. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3:00 AM MONDAY...MEDIUM RANGE MODELS HAVE REVERTED BACK TO A LESS AMPLIFIED SOLUTION FOR THE END OF THE PERIOD AS THE MASSIVE RIDGE BUILDS BACK TO THE NORTHEAST. THE OPERATIONAL ECMWF CONTINUES TO ADVERTISE SLIGHTLY MORE AMPLITUDE WHEN COMPARED TO THE GFS BUT THIS SEEMS TO BE A RESULT OF FEEDBACK COURTESY OF THE REMAINING VORTICITY FROM TD TEN THAT MAKES IT ALL THE WAY TO THE ATLANTIC. AT THE SURFACE...AN OLD BOUNDARY WILL MOVE BACK WELL TO THE NORTH OF THE AREA LATER SATURDAY AND SUNDAY. PRECIPITABLE WATERS INCREASE TO OVER TWO INCHES AS A WEAK BERMUDA HIGH BUILDS IN AT THE SURFACE. FORCING WILL BE NEGLIGIBLE BUT HAVE INTRODUCED POPS FOR SATURDAY AND SUNDAY WITH THE MORNING UPDATE. NO CHANGES TO TEMPERATURE FORECAST WHICH CONTINUES ABOVE CLIMATOLOGY. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 12Z...IR SATELLITE IMAGERY INDICATES SCATTERED TO BROKEN MID LEVEL CLOUDS AT THE COASTAL TERMINALS EXTENDING NORTHWEST TO NEAR THE LBT TERMINAL. WATER VAPOR IMAGERY SHOWS DRY AIR JUST INLAND OF THE IMMEDIATE COAST. AN ISOLATED THUNDERSTORM HAS DEVELOPED JUST EAST OF MYR THIS MORNING. THIS CELL LIKELY DEVELOPED ON AN OUTFLOW BOUNDARY EMANATING FROM THUNDERSTORMS THAT OCCURRED EARLIER THIS MORNING SOUTHEAST OF THE MYR TERMINAL. DO EXPECT THIS CELL TO DIRECTLY AFFECT THE MYR TERMINAL AS IT MOVES TO THE SOUTHEAST. HIGH CONFIDENCE VFR FORECAST FOR ALL TERMINALS THROUGH THIS EVENING. NORTHEAST WINDS AT 5 KNOTS OR LESS THIS MORNING WILL BECOME EAST TO SOUTHEAST AT 8-15 KNOTS BY MID-LATE MORNING...HIGHEST AT THE COASTAL TERMINALS. MODELS ARE DEPICTING THE DEEPEST MOISTURE WILL REMAIN EAST OF THE TERMINALS TODAY. EXPECT MID LEVEL CEILINGS CURRENTLY AFFECTING THE COASTAL TERMINALS TO END BY MID MORNING AS DRIER AIR FILTERS IN. BUT EASTERLY WINDS IN THE LOW LEVELS WILL ADVECT LOW LEVEL MOISTURE INLAND AND THIS SHOULD ALLOW FOR CUMULUS FORMATION WITH BASES 3-4K BY MID MORNING. A RESULTANT BOUNDARY IS EXPECTED TO DEVELOP LATER THIS MORNING AND MOVE INLAND. BY AFTERNOON THERE IS A CHANCE OF ISOLATED SHOWER DEVELOPMENT ALONG THE BOUNDARY...MOST LIKELY JUST INLAND OF MYR/CRE. BUT LIMITED INSTABILITY...DRY AIR...WEAK CAPPING AND LACK OF LARGE SCALE LIFT SHOULD KEEP ACTIVITY ISOLATED AND NEGATE THUNDERSTORM DEVELOPMENT. BY SUNSET ANY SHOWER ACTIVITY SHOULD END. WINDS SHOULD BECOME LIGHT AND VARIABLE BY 00-01Z AT FLO/LBT AND AT THE COASTAL TERMINALS BY 02-03Z. TIME HEIGHT IMAGES SUGGEST A POSSIBILITY OF MVFR CEILINGS 1-2K DEVELOPING AFTER MIDNIGHT. THERE IS LOW CONFIDENCE OF OCCURRENCE ATTM. FOG DEVELOPMENT SEEMS MORE LIKELY WITH MODERATE CONFIDENCE THAT MVFR VISIBILITIES WILL DEVELOP. IFR VISIBILITIES COULD DEVELOP AT THE FLO/LBT TERMINALS...BUT CONFIDENCE IS LOW ATTM. WILL INDICATE MVFR VISIBILITIES DEVELOPING AT ALL TERMINALS AFTER MIDNIGHT. EXTENDED OUTLOOK...LOW CONFIDENCE IFR VISIBILITIES DUE TO EARLY MORNING FOG EACH MORNING AT FLO/LBT. OTHERWISE...NO SIG WX EXPECTED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM MONDAY...LIGHT ON SHORE NE-E FLOW WILL EXIST AROUND HIGH PRESSURE CENTERED TO NORTH OF COASTAL WATERS. SEAS WILL BE 3 FT OR LESS OVER MOST WATERS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3:00 AM MONDAY...WEAK GRADIENT INITIALLY WILL INCREASE LATER WEDNESDAY AS WINDS INCREASE FROM AROUND 10 KNOTS OR LESS TO AROUND 15 KNOTS FROM THE SOUTHWEST LATER WEDNESDAY. THIS INCREASE COURTESY OF AN APPROACHING FRONT. FRONT MOVES ACROSS BY THURSDAY MORNING WITH THE FLOW VEERING TO NW AND REMAINING LIGHT. WAVEWATCH SEAS REMAIN CONSISTENT AROUND 1-2 FEET. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3:00 AM MONDAY...NW WINDS INITIALLY WILL VEER TO NE BY THE END OF THE PERIOD AS HIGH PRESSURE...CENTERED OVER THE MID ATLANTIC GRUDGINGLY HANGS ON. GRADIENT IS WEAK HOWEVER AND WIND SPEEDS WILL REMAIN BELOW 10 KNOTS. WITH LITTLE TROPICAL ACTIVITY IN THE OPEN ATLANTIC...SIGNIFICANT WAVE HEIGHTS WILL REMAIN LOW IN A 2-3 FOOT RANGE WITH THE SPECTRUM ALMOST EXCLUSIVELY WIND WAVES. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...RGZ SHORT TERM...SHK LONG TERM...SHK AVIATION...MRR 000 FXUS62 KRAH 061403 AFDRAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RALEIGH NC 1000 AM EDT MON SEP 6 2010 .SYNOPSIS... A DRY HIGH PRESSURE RIDGE WILL EXTEND ACROSS NC THROUGH THE MIDDLE OF THE WEEK. A WEAK COLD FRONT WILL THEN DRIFT ACROSS THE STATE WEDNESDAY NIGHT. && .NEAR TERM /TODAY THROUGH TUESDAY NIGHT/... AS OF 950 AM MONDAY... CHANGES TO THE FORECAST ARE VERY MINOR THIS MORNING. THE AXIS OF A SHORTWAVE TROUGH IS CROSSING THE AREA THIS MORNING...WITH BROAD HEIGHT RISES ALOFT BEHIND THE TROUGH FROM THE EASTERN GREAT LAKES TO THE TENNESSEE VALLEY. SURFACE HIGH PRESSURE LOCATED NEAR THE MASON-DIXON LINE IS FORECAST TO SLIDE OFFSHORE TODAY...WITH WEAK WARM ADVECTION AND LIGHT EAST-SOUTHEASTERLY FLOW KICKING IN OVER THE CWA. PWS CONTINUE TO BE LOW THIS MORNING...WITH 0.83" OBSERVED AT KGSO AT 12Z. WILL SEE SOME PATCHY FLAT CU WHERE MORNING STRATUS FROM LEXINGTON TO SANFORD HAS LIFTED TO 5-7K FT...AND ALSO OVER THE SOUTHERN COASTAL PLAIN AS SOME COASTAL MOISTURE ADVECTS INLAND. OTHERWISE EXPECT MOSTLY SUNNY SKIES. THE 06Z NAM VERIFIED BEST WITH 850MB TEMPS THIS MORNING....AND WITH FORECAST SOUNDINGS SHOWING MIXING UP TO 800MB...HAVE NUDGED HIGHS TOWARD THE NAM WITH 86-90 NE-SW. -SMITH LOW TEMPS TUE WILL BE AT LEAST SEVERAL DEGREES WARMER THAN THIS MORNING DUE TO AIRMASS MODIFICATION/RISING THICKNESSES...IN THE UPPER 50S TO LOWER 60S. TUESDAY AND TUESDAY NIGHT: THE H5 RIDGE WILL PEAK IN STRENGTH OVER THE SOUTHEAST STATES/ CAROLINAS ON TUE BEFORE WEAKENING AND FLATTENING OUT TUE NIGHT AND WED AS A POTENT H5 LOW MOVES EAST ACROSS THE GREAT LAKES INTO NEW ENGLAND. RELATIVELY STRONG 1024 MB SFC HIGH PRESSURE OFFSHORE THE MID-ATLANTIC (AND EXTENDING SW INTO THE CAROLINAS) IS PROGGED TO WEAKEN TUE AS A PRE-FRONTAL TROUGH APPROACHES FROM THE WEST...WITH THE PRE-FRONTAL TROUGH OVER CENTRAL NC BY 12Z WED. FCST SOUNDINGS ARE CONSISTENT WITH SYNOPTIC SUBSIDENCE DURING THE DAY TUE...WITH WARM/DRY MID-LEVELS AND BELOW NORMAL PWAT VALUES AT OR BELOW 1". AS A RESULT...THE FORECAST WILL REMAIN DRY WITH SUNNY SKIES (ASIDE FROM PERHAPS A FEW FLAT DIURNAL CU) AND NO CHANCE FOR PRECIPITATION. THE PRE-FRONTAL TROUGH WILL ALLOW FOR SOME LOW LEVEL CONVERGENCE AND MOISTENING WHEN IT MOVES INTO THE AREA TUE NIGHT...HOWEVER...UPPER LEVEL FORCING WILL BE ABSENT...AND THE LOW-LEVEL FORCING/MOISTURE WILL BE INADEQUATE TO SUPPORT ANT PRECIPITATION. WILL CONTINUE A DRY FCST TUE NIGHT...WITH PARTLY TO MOSTLY CLOUDY SKIES PRIMARILY ASSOC/W UPPER LEVEL CLOUD COVER MOVING INTO THE AREA VIA WESTERLY FLOW ALOFT. 1000-850 MB THICKNESSES FURTHER INCREASE TO 1415-1420 METERS UNDER THE STRENGTHENING H5 RIDGE TUE...INDICATING HIGH TEMPS A FEW DEGREES WARMER THAN TODAY...IN THE UPPER 80S TO LOWER 90S. LOWS TUE NIGHT WILL BE TEMPERED SOMEWHAT BY INCREASING UPPER LEVEL CLOUD COVER AND WEAK WARM ADVECTION. WILL FCST LOWS IN THE LOWER/MID 60S...CLOSE TO MOS GUIDANCE. -VINCENT && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 215 AM MONDAY... WEDNESDAY AND WEDNESDAY NIGHT: CLOSED UPPER LOW IS EXPECTED TO CONTINUE TRACKING EASTWARD ACROSS SOUTHERN ONTARIO INTO SOUTHERN QUEBEC AND NEW ENGLAND ON WEDNESDAY INTO WEDNESDAY NIGHT ALLOWING THE MID/UPPER LEVEL RIDGE TO DAMPEN ACROSS OUR AREA. THIS WILL ALLOW A TRAILING COLD FRONT TO MOVE THROUGH CENTRAL NC WEDNESDAY EVENING INTO THURSDAY MORNING. GIVEN THE GENERALLY WESTERLY FLOW PRECEDING THE FRONT WOULD EXPECT LITTLE IF ANY PRECIP WITH THIS FRONT. HOWEVER... MODELS NOW SHOW PW`S INCREASING TO NEAR 1.7 INCHES ACROSS THE SOUTHERN HALF OF THE CWA JUST AHEAD OF THE FRONT. HOWEVER... WILL LEAVE MENTION OF PRECIP OUT FOR NOW AS MODELS DO NOT SHOW MUCH IN THE WAY...IF ANY...OF QPF. HIGH TEMPS ON WEDNESDAY LOOK TO BE IN THE LOWER TO MID 90S... DESPITE THE DAMPENING OF THE RIDGE AND MID AND HIGH LEVEL CLOUD COVERAGE INCREASING DURING THE AFTERNOON AHEAD OF THE FRONT. HOWEVER...LOW LEVEL THICKNESS VALUES INCREASE FROM TUESDAY AFTERNOON SOME 10 TO 15 METERS. THUS...LOWER TO MID 90S LOOK GOOD. EXPECT LOWS THURSDAY MORNING TO GENERALLY BE IN THE MID TO UPPER 60S...WITH PERHAPS SOME LOWER 60S ACROSS THE NORTH WHERE WE SHOULD BEGIN TO CLEAR OUT BY SUNRISE. THURSDAY AND THURSDAY NIGHT: HIGH PRESSURE AT THE SURFACE IS EXPECTED TO BUILD INTO THE AREA FROM THE NORTH DURING THIS TIME FRAME...AS 500 HPA HEIGHT BEGIN TO SLOWLY RECOVER AS RIDGING ACROSS THE CENTRAL U.S. SLOWLY TRANSLATES EASTWARD. THIS SHOULD LEAD TO A PLEASANT DAY ON THURSDAY AFTERNOON...WITH LOWER DEWPOINTS. WITH GENERALLY MOSTLY SUNNY SKIES EXPECT TEMPS TO TOP OUT IN THE UPPER 80S TO NEAR 90. DRY CONDITIONS ARE EXPECTED TO CONTINUE INTO THURSDAY NIGHT...WITH LOWS EXPECTED TO FALL INTO THE LOWER TO MID 60S. && .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 235 AM MONDAY... FRIDAY THROUGH SUNDAY: MEDIUM RANGE MODELS GENERALLY AGREE ON THE UPPER LEVEL PATTERN AT THE START OF THE MEDIUM RANGE (TROUGH ACROSS THE WESTERN U.S... RIDGE CENTRAL U.S... AND TROUGH ALONG THE EAST COAST). HOWEVER... AMPLIFICATION AND SUBSEQUENTLY THE PROGRESSION OF THE PATTERN (GFS FASTER... ECMWF SLOWER) ARE IN QUESTION. THIS WILL NO DOUBT AFFECT THE FORECAST FOR LATE NEXT WEEK INTO THE WEEKEND. ALL MEDIUM RANGE GUIDANCE DEPICTS REMNANTS FROM A TROPICAL SYSTEM CURRENTLY LOCATED ACROSS PORTIONS OF THE WESTERN GULF OF MEXICO... TRACKING AROUND THE CENTER OF THE MID LEVEL RIDGE (THE DEEP SOUTH) AND ACROSS THE MID ATLANTIC OR SOUTHEAST BY FRIDAY NIGHT INTO SATURDAY. HOWEVER... PLACEMENT AND TIMING OF THIS FEATURE ARE STILL IN QUESTION. FOR NOW WILL CONTINUE A DRY FORECAST FOR FRIDAY AND ADD ONLY A SLIGHT CHANCE OF SHOWERS FOR SATURDAY. HOWEVER... POPS MAY BE NEED TO ADDED FOR FRIDAY NIGHT AND INCREASED ON SATURDAY AS WELL IN LATER SHIFT WHEN MODELS BEGIN TO CONVERGE ON A SOLUTION. FOR SUNDAY... MODELS CONTINUE TO INDICATE THE POTENTIAL FOR ANOTHER FRONT MAKING IT INTO/APPROACHING THE AREA EITHER NEXT SUNDAY OR EARLY NEXT WEEK. HOWEVER... WILL THE LEAVE THE FORECAST DRY FOR SUNDAY... GIVEN THE UNCERTAINTY AND TIMING DIFFERENCES. HIGHS DURING THIS TIME ARE EXPECTED TO BE IN THE UPPER 80S TO AROUND 90 AND LOWS IN THE MID TO UPPER 60S. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 630 AM MONDAY... 24-HR TAF PERIOD: VFR CONDITIONS IN SUNNY/CLEAR SKIES WILL PREVAIL THROUGH THE TAF PERIOD IN ASSOC/W A STRENGTHENING UPPER LEVEL RIDGE AND DRY ATMOSPHERE OVER THE CAROLINAS. LIGHT/VARIABLE OR LIGHT EAST/NE WINDS AND MOSTLY CLEAR SKIES WILL PERSIST THROUGH 12Z TUE AS HIGH PRESSURE REMAINS ANCHORED NEAR OR OVER THE AREA. WEAK WARM ADVECTION IN ASSOC/W A SOUTHERLY RETURN FLOW WILL DEVELOP AT THE END OF THE TAF PERIOD...AND A SHORT PERIOD OF MVFR/IFR CEILINGS CANNOT BE RULED OUT AT ANY LOCATION IN THE 08-13Z TIME FRAME TUE MORNING. LOOKING AHEAD: VFR CONDITIONS ARE EXPECTED TO PREDOMINATE THROUGH MID/LATE WEEK. A RIDGE ALOFT WILL REMAIN OVER THE AREA ON TUE...WITH CONTINUED CLEAR SKIES AND LIGHT SOUTHERLY WINDS. A WEAK PRE-FRONTAL TROUGH WILL MOVE INTO THE AREA BY 12Z WED...AND A WEAK COLD FRONT WILL SURGE SOUTHWARD THROUGH CENTRAL NC WED EVENING/NIGHT. AT THIS TIME THE FRONTAL PASSAGE IS EXPECTED TO REMAIN DRY...WITH LIGHT WINDS SHIFTING TO THE NORTH BEHIND THE FRONT WED NIGHT. DRY HIGH PRESSURE WILL BUILD TOWARD CENTRAL NC BEHIND THE FRONT ON THU/FRI. -VINCENT && .RAH WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...VINCENT NEAR TERM...VINCENT/SMITH SHORT TERM...BSD LONG TERM...BSD AVIATION...VINCENT 000 FXUS62 KMHX 061300 AFDMHX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC 900 AM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE CENTER TO THE NORTH THIS MORNING WILL SLIDE OFFSHORE THIS AFTERNOON THEN EXTEND SOUTHWEST INTO THE AREA ON TUESDAY. A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST LATE WEDNESDAY AND CROSS THE AREA WEDNESDAY NIGHT AND EARLY THURSDAY. HIGH PRESSURE WILL BUILD TO THE NORTH FRIDAY AND SLIDE OFFSHORE SATURDAY. ANOTHER COLD FRONT WILL MOVE INTO THE REGION SUNDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... AS OF 9 AM MON...NO CHANGES EXPECTED TODAY. THICKER CLOUDS EXPECTED TO REMAIN OFFSHORE WITH SKIES RANGING FROM MAINLY SUNNY INLAND TO PC S CST. HIGHS MAINLY MID TO UPR 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... SFC HIGH PRES TO THE NE OF THE AREA TONIGHT WILL BEGIN TO EXTEND BACK TO THE SW AS MID LEVEL RIDGING BUILDS EAST ON TUE. EXPECT MCLR SKIES WITH NO REAL THREAT OF PRECIP. WITH LIGHT WINDS WILL CONT TO HAVE GOOD RADIATIONAL COOLING AT NIGHT SO WENT AOB COOLEST GUIDANCE WITH UPR 50S TONIGHT/LOWER TO MID 60S TUE NIGHT INLAND FROM THE COAST. AFTN HIGHS TUE WILL BE A FEW DEGS WARMER THAN TODAY...MAINLY IN THE MID TO UPR 80S...HOWEVER HUMIDITY LEVELS WILL REMAIN COMFORTABLE. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... WEAK COLD FRONT WILL APPROACH FROM THE NW LATER WED AND CROSS THE AREA WED NIGHT/EARLY THU MORN. MOISTURE STILL LOOKS VERY LIMITED SO WILL NOT FCST ANY PRECIP AS YET. HIGH PRES WILL PASS TO THE N THU AND SLIDE OFFSHORE FRI. ISOLD POPS FRI NIGHT AND SAT PER GFS/ECMWF WITH RETURN FLOW AND WEAK SRT WAVE CROSSING. KEPT WEEKEND DRY HOWEVER ANOTHER FRONT WILL BE MOVING INTO THE AREA LATE SAT NIGHT OR SUN SO MAY EVENTUALLY NEED TO ADD SOME PRECIP. SHLD SEE SOME LOWER 90S WED AHEAD OF THE FRONT THEN MAINLY MID/UPR 80S AFTER THAT. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... AS OF 9 AM MON...VFR TODAY WITH ANY CIGS OVER CSTL SITES WELL ABOVE 3000 FT. GENERALLY VFR EXPECTED TROUGH THE REST OF THE PERIOD WITH PATCHY LATE NIGHT/EARLY MORNING FOG POSSIBLE EACH MORNING AS THE AIRMASS MODERATES. A FRONT WILL APPROACH RTES LATE WED AND MOVE S ACROSS THE AREA LATE THU NIGHT...BUT WITH LIMITED MOISTURE AND WEAK DYNAMICS NOT EXPECTING MUCH IF ANY PCPN. && .MARINE... AS OF 9 AM MON...NO CHANGES TODAY WITH HIGH PRES TO THE NE PRODUCING NE WINDS MAINLY 10 TO 15 KTS WITH SEAS 2 TO 4 FT. PREV DISC...HIGH PRES TO THE N WILL SLIDE OF THE MID ATLANTIC COAST TODAY WHILE A FRONT REMAINS STALLED ACROSS THE OFFSHORE WATERS. GRADIENTS TIGHTEN SLIGHTLY AS THE HIGH MOVES OFFSHORE BRINGING NELY WINDS AROUND 10-15 KT. GRADIENTS RELAX TONIGHT THROUGH TUE NIGHT AS THE HIGH SLOWLY MIGRATES SWD ACROSS THE WRN ATLANTIC WITH WINDS GRADUALLY SHIFING TO E...THEN SELY GENERALLY AOB 10 KT. WINDS SHIFT TO SWLY AND INCREASE TO 10-15 KT WED WITH THE HIGH CENTERED SE OF THE REGION AND A COLD FRONT APPROACHING FROM THE W. THE FRONT CROSSES THE WATERS LATE WED NIGHT INTO EARLY THU MORNING WITH WINDS BECOMING NLY AND GRADUALLY DIMINISHING. WAVEWATCH KEEPS SEAS AOB 3 FT TODAY AND TONIGHT...HOWEVER SWAN DOES BUILD SEAS UP TO 4 FT WHICH SEEMS PLAUSABLE AS I HAVE SLIGHT STRONGER WINDS THAN THE GFS. OTHERWISE...EXPECT SEAS AOB 3 FT THROUGH WED...WHICH WILL THEN BUILD UP TO 4 FT LATE WED AND THU WITH A BIT STRONGER WINDS ASSOC WITH THE FRONTAL PASSAGE. && .MHX WATCHES/WARNINGS/ADVISORIES... NC...NONE. MARINE...NONE. && $$ SYNOPSIS...BTC NEAR TERM...RF SHORT TERM...BTC/RF LONG TERM...BTC/RF AVIATION...RF/SK MARINE...RF/SK 000 FXUS62 KILM 061142 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 742 AM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO PROVIDE NICE WEATHER THROUGH WEDNESDAY. A WEAK FRONT WILL MOVE ACROSS THE AREA THURSDAY WITH LITTLE IMPACT ON THE WEATHER. A SLIGHT CHANCE OF SHOWERS WILL ENTER THE PICTURE NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3:00 AM MONDAY...ONE THUNDERSTORM BRUSHING THE COAST...MOVING NORTHEAST BETWEEN GEORGETOWN AND MYRTLE BEACH...ASSOCIATED WITH AN OPEN WAVE ALONG A FRONTAL BOUNDARY THAT IS JUST ALONG AND OFFSHORE. THIS KINK IN THE FRONT BEING INDUCED BY A SHORT WAVE CURRENTLY TRANSITING THE AREA. ONCE THIS PASSES...EXPECT A QUIET DAY AS HIGH PRESSURE CENTERED TO OUR NORTH MAINTAINS POSITION AND A VERY DEEP...DRY AIR MASS CONTINUES TO OVERSPREAD THE AREA. WATER VAPOR SATELLITE LOOPS AND MODEL SOUNDINGS DEPICT THIS DRY AIR MASS WELL. CHANCES FOR PRECIP WILL REMAIN LOW TO ZERO WITH BEST CHANCES ALONG THE COAST SOUTH OF CAPE FEAR IN CLOSEST VICINITY TO THE FRONT. TEMPERATURES VERY SIMILAR TO YESTERDAY WITH LITTLE CHANGE IN THE THERMAL RIDGE OR OVERALL FLOW. MID 80S ALONG THE COAST TO UPPER 80S INLAND FOR HIGHS...MID 60S FOR LOWS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3:00 AM MONDAY...MASSIVE RIDGE WILL DOMINATE THROUGH MUCH OF THE PERIOD WITH HIGH PRESSURE EXTENDING OFF TO THE NORTHEAST AT THE SURFACE. RIDGE GETS SUPPRESSED TO THE SOUTH LATER WEDNESDAY AS A STRONG SHORTWAVE MOVES ACROSS THE GREAT LAKES. THIS ALLOWS A SURFACE FRONT TO MOVE ACROSS THE AREA BY THURSDAY MORNING. THE GFS AND ECMWF ARE DRY WITH THE NAM ADVERTISING SOME LIGHT QPF VIA SHALLOW FRONTAL FORCING. DID TREND UP POPS A BIT TO ADDRESS THIS POSSIBILITY WHILE REMAINING BELOW THE 15 PERCENT THRESHOLD WHICH WARRANTS MENTION IN THE ZONES. VERIFICATION NUMBERS OVER THE PAST 30 DAYS SHOW THE BIAS CORRECTED ADJUSTED MET NUMBERS ARE THE BEST OPTION REGARDING TEMPERATURES THROUGH THE PERIOD. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3:00 AM MONDAY...MEDIUM RANGE MODELS HAVE REVERTED BACK TO A LESS AMPLIFIED SOLUTION FOR THE END OF THE PERIOD AS THE MASSIVE RIDGE BUILDS BACK TO THE NORTHEAST. THE OPERATIONAL ECMWF CONTINUES TO ADVERTISE SLIGHTLY MORE AMPLITUDE WHEN COMPARED TO THE GFS BUT THIS SEEMS TO BE A RESULT OF FEEDBACK COURTESY OF THE REMAINING VORTICITY FROM TD TEN THAT MAKES IT ALL THE WAY TO THE ATLANTIC. AT THE SURFACE...AN OLD BOUNDARY WILL MOVE BACK WELL TO THE NORTH OF THE AREA LATER SATURDAY AND SUNDAY. PRECIPITABLE WATERS INCREASE TO OVER TWO INCHES AS A WEAK BERMUDA HIGH BUILDS IN AT THE SURFACE. FORCING WILL BE NEGLIGIBLE BUT HAVE INTRODUCED POPS FOR SATURDAY AND SUNDAY WITH THE MORNING UPDATE. NO CHANGES TO TEMPERATURE FORECAST WHICH CONTINUES ABOVE CLIMATOLOGY. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AS OF 12Z...IR SATELLITE IMAGERY INDICATES SCATTERED TO BROKEN MID LEVEL CLOUDS AT THE COASTAL TERMINALS EXTENDING NORTHWEST TO NEAR THE LBT TERMINAL. WATER VAPOR IMAGERY SHOWS DRY AIR JUST INLAND OF THE IMMEDIATE COAST. AN ISOLATED THUNDERSTORM HAS DEVELOPED JUST EAST OF MYR THIS MORNING. THIS CELL LIKELY DEVELOPED ON AN OUTFLOW BOUNDARY EMANATING FROM THUNDERSTORMS THAT OCCURRED EARLIER THIS MORNING SOUTHEAST OF THE MYR TERMINAL. DO EXPECT THIS CELL TO DIRECTLY AFFECT THE MYR TERMINAL AS IT MOVES TO THE SOUTHEAST. HIGH CONFIDENCE VFR FORECAST FOR ALL TERMINALS THROUGH THIS EVENING. NORTHEAST WINDS AT 5 KNOTS OR LESS THIS MORNING WILL BECOME EAST TO SOUTHEAST AT 8-15 KNOTS BY MID-LATE MORNING...HIGHEST AT THE COASTAL TERMINALS. MODELS ARE DEPICTING THE DEEPEST MOISTURE WILL REMAIN EAST OF THE TERMINALS TODAY. EXPECT MID LEVEL CEILINGS CURRENTLY AFFECTING THE COASTAL TERMINALS TO END BY MID MORNING AS DRIER AIR FILTERS IN. BUT EASTERLY WINDS IN THE LOW LEVELS WILL ADVECT LOW LEVEL MOISTURE INLAND AND THIS SHOULD ALLOW FOR CUMULUS FORMATION WITH BASES 3-4K BY MID MORNING. A RESULTANT BOUNDARY IS EXPECTED TO DEVELOP LATER THIS MORNING AND MOVE INLAND. BY AFTERNOON THERE IS A CHANCE OF ISOLATED SHOWER DEVELOPMENT ALONG THE BOUNDARY...MOST LIKELY JUST INLAND OF MYR/CRE. BUT LIMITED INSTABILITY...DRY AIR...WEAK CAPPING AND LACK OF LARGE SCALE LIFT SHOULD KEEP ACTIVITY ISOLATED AND NEGATE THUNDERSTORM DEVELOPMENT. BY SUNSET ANY SHOWER ACTIVITY SHOULD END. WINDS SHOULD BECOME LIGHT AND VARIABLE BY 00-01Z AT FLO/LBT AND AT THE COASTAL TERMINALS BY 02-03Z. TIME HEIGHT IMAGES SUGGEST A POSSIBILITY OF MVFR CEILINGS 1-2K DEVELOPING AFTER MIDNIGHT. THERE IS LOW CONFIDENCE OF OCCURRENCE ATTM. FOG DEVELOPMENT SEEMS MORE LIKELY WITH MODERATE CONFIDENCE THAT MVFR VISIBILITIES WILL DEVELOP. IFR VISIBILITIES COULD DEVELOP AT THE FLO/LBT TERMINALS...BUT CONFIDENCE IS LOW ATTM. WILL INDICATE MVFR VISIBILITIES DEVELOPING AT ALL TERMINALS AFTER MIDNIGHT. EXTENDED OUTLOOK...LOW CONFIDENCE IFR VISIBILITIES DUE TO EARLY MORNING FOG EACH MORNING AT FLO/LBT. OTHERWISE...NO SIG WX EXPECTED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3:00 AM MONDAY...LIGHT NE TO E FLOW WILL MAINTAIN THROUGH THE PERIOD AS HIGH PRESSURE REMAINS CENTERED TO OUR NORTH. SEAS WILL BE A FOOT EITHER SIDE OF 3 FT. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3:00 AM MONDAY...WEAK GRADIENT INITIALLY WILL INCREASE LATER WEDNESDAY AS WINDS INCREASE FROM AROUND 10 KNOTS OR LESS TO AROUND 15 KNOTS FROM THE SOUTHWEST LATER WEDNESDAY. THIS INCREASE COURTESY OF AN APPROACHING FRONT. FRONT MOVES ACROSS BY THURSDAY MORNING WITH THE FLOW VEERING TO NW AND REMAINING LIGHT. WAVEWATCH SEAS REMAIN CONSISTENT AROUND 1-2 FEET. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3:00 AM MONDAY...NW WINDS INITIALLY WILL VEER TO NE BY THE END OF THE PERIOD AS HIGH PRESSURE...CENTERED OVER THE MID ATLANTIC GRUDGINGLY HANGS ON. GRADIENT IS WEAK HOWEVER AND WIND SPEEDS WILL REMAIN BELOW 10 KNOTS. WITH LITTLE TROPICAL ACTIVITY IN THE OPEN ATLANTIC...SIGNIFICANT WAVE HEIGHTS WILL REMAIN LOW IN A 2-3 FOOT RANGE WITH THE SPECTRUM ALMOST EXCLUSIVELY WIND WAVES. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...REK SHORT TERM...SHK LONG TERM...SHK AVIATION...MRR 000 FXUS62 KILM 061139 CCA AFDILM AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE WILMINGTON NC 737 AM EDT MON SEP 6 2010 .SYNOPSIS... HIGH PRESSURE WILL CONTINUE TO PROVIDE NICE WEATHER THROUGH WEDNESDAY. A WEAK FRONT WILL MOVE ACROSS THE AREA THURSDAY WITH LITTLE IMPACT ON THE WEATHER. A SLIGHT CHANCE OF SHOWERS WILL ENTER THE PICTURE NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3:00 AM MONDAY...ONE THUNDERSTORM BRUSHING THE COAST...MOVING NORTHEAST BETWEEN GEORGETOWN AND MYRTLE BEACH...ASSOCIATED WITH AN OPEN WAVE ALONG A FRONTAL BOUNDARY THAT IS JUST ALONG AND OFFSHORE. THIS KINK IN THE FRONT BEING INDUCED BY A SHORT WAVE CURRENTLY TRANSITING THE AREA. ONCE THIS PASSES...EXPECT A QUIET DAY AS HIGH PRESSURE CENTERED TO OUR NORTH MAINTAINS POSITION AND A VERY DEEP...DRY AIRMASS CONTINUES TO OVERSPREAD THE AREA. WATER VAPOR SATELLITE LOOPS AND MODEL SOUNDINGS DEPICT THIS DRY AIRMASS WELL. CHANCES FOR PRECIP WILL REMAIN LOW TO ZERO WITH BEST CHANCES ALONG THE COAST SOUTH OF CAPE FEAR IN CLOSEST VICINITY TO THE FRONT. TEMPERATURES VERY SIMILAR TO YESTERDAY WITH LITTLE CHANGE IN THE THERMAL RIDGE OR OVERALL FLOW. MID 80S ALONG THE COAST TO UPPER 80S INLAND FOR HIGHS...MID 60S FOR LOWS. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3:00 AM MONDAY...MASSIVE RIDGE WILL DOMINATE THROUGH MUCH OF THE PERIOD WITH HIGH PRESSURE EXTENDING OFF TO THE NORTHEAST AT THE SURFACE. RIDGE GETS SUPPRESSED TO THE SOUTH LATER WEDNESDAY AS A STRONG SHORTWAVE MOVES ACROSS THE GREAT LAKES. THIS ALLOWS A SURFACE FRONT TO MOVE ACROSS THE AREA BY THURSDAY MORNING. THE GFS AND ECMWF ARE DRY WITH THE NAM ADVERTISING SOME LIGHT QPF VIA SHALLOW FRONTAL FORCING. DID TREND UP POPS A BIT TO ADDRESS THIS POSSIBILITY WHILE REMAINING BELOW THE 15 PERCENT THRESHOLD WHICH WARRANTS MENTION IN THE ZONES. VERIFICATION NUMBERS OVER THE PAST 30 DAYS SHOW THE BIAS CORRECTED ADJUSTED MET NUMBERS ARE THE BEST OPTION REGARDING TEMPERATURES THROUGH THE PERIOD. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 3:00 AM MONDAY...MEDIUM RANGE MODELS HAVE REVERTED BACK TO A LESS AMPLIFIED SOLUTION FOR THE END OF THE PERIOD AS THE MASSIVE RIDGE BUILDS BACK TO THE NORTHEAST. THE OPERATIONAL ECMWF CONTINUES TO ADVERTISE SLIGHTLY MORE AMPLITUDE WHEN COMPARED TO THE GFS BUT THIS SEEMS TO BE A RESULT OF FEEDBACK COURTESY OF THE REMAINING VORTICITY FROM TD TEN THAT MAKES IT ALL THE WAY TO THE ATLANTIC. AT THE SURFACE...AN OLD BOUNDARY WILL MOVE BACK WELL TO THE NORTH OF THE AREA LATER SATURDAY AND SUNDAY. PRECIPITABLE WATERS INCREASE TO OVER TWO INCHES AS A WEAK BERMUDA HIGH BUILDS IN AT THE SURFACE. FORCING WILL BE NEGLIGIBLE BUT HAVE INTRODUCED POPS FOR SATURDAY AND SUNDAY WITH THE MORNING UPDATE. NO CHANGES TO TEMPERATURE FORECAST WHICH CONTINUES ABOVE CLIMATOLOGY. && .AVIATION /07Z MONDAY THROUGH FRIDAY/... AS OF 06Z...HIGH CONFIDENCE IN VFR THROUGH THE VALID PERIOD WITH SCT CLOUD COVER AND LIGHT WINDS. DISSIPATING COLD FRONT WELL OFFSHORE IS CONTINUING TO THROW MID AND HIGH LEVEL CLOUD COVER ACROSS THE COASTAL TERMINALS...AND THIS WILL LIKELY CONTINUE THROUGH THE OVERNIGHT. THIS CLOUD COVER...COMBINED WITH WINDS ABOVE CALM...WILL CAUSE A LATE START TO RADIATIONAL COOLING OVERNIGHT AND HAS PROMPTED REMOVAL OF ANY MVFR FROM THE CRE/MYR TAFS. DO NOT HAVE ANY VSBY RESTRICTIONS INLAND EITHER...EVEN THOUGH RADIATIONAL COOLING EFFECTS WILL BE MAXIMIZED THERE. HAVE NOTICED BOTH GFS MOS AND LAMP GUIDANCE WANT TO BRING MVFR TO LBT...BUT XOVER TEMP THERE IS 53 AND THIS WILL NOT BE MET SO HAVE KEPT VSBYS UNRESTRICTED AT ALL SITES OVERNIGHT. AFTER SUNRISE ANY MVFR WILL RAPIDLY BURN OFF LEADING TO ANOTHER DAY OF VFR WITH EAST WINDS AROUND 10 KTS. MORE CU IS ANTICIPATED ON MONDAY THAN THE PAST FEW DAYS DUE TO SLIGHTLY HIGHER TD/S...BUT WILL BE AT VFR HEIGHTS SO NO RESTRICTIONS ARE EXPECTED. WITH SLIGHTLY HIGHER TD/S...ANOTHER S/W PROGGED TO ROTATE AROUND THE BASE OF UPPER TROUGH...AND SINCE CONVECTIVE CAP DID BREAK SUNDAY...THERE MAY BE AN ISOLATED SHOWER ON MONDAY. HAVE NOT MENTIONED IN TAFS DUE TO ISOLATED NATURE...BUT IT IS NOT OUT OF THE QUESTION A SHOWER COULD IMPACT A TERMINAL. AFTER DARK CONVECTIVE CLOUD COVER WILL RAPIDLY DISSIPATE LEAVING MOSTLY CLEAR SKY CONDITIONS WITH LIGHT WINDS. EXTENDED OUTLOOK...MORNING FOG POSSIBLE EACH MORNING. OTRW...VFR THROUGH THE EXTENDED. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3:00 AM MONDAY...LIGHT NE TO E FLOW WILL MAINTAIN THROUGH THE PERIOD AS HIGH PRESSURE REMAINS CENTERED TO OUR NORTH. SEAS WILL BE A FOOT EITHER SIDE OF 3 FT. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 3:00 AM MONDAY...WEAK GRADIENT INITIALLY WILL INCREASE LATER WEDNESDAY AS WINDS INCREASE FROM AROUND 10 KNOTS OR LESS TO AROUND 15 KNOTS FROM THE SOUTHWEST LATER WEDNESDAY. THIS INCREASE COURTESY OF AN APPROACHING FRONT. FRONT MOVES ACROSS BY THURSDAY MORNING WITH THE FLOW VEERING TO NW AND REMAINING LIGHT. WAVEWATCH SEAS REMAIN CONSISTENT AROUND 1-2 FEET. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 3:00 AM MONDAY...NW WINDS INITIALLY WILL VEER TO NE BY THE END OF THE PERIOD AS HIGH PRESSURE...CENTERED OVER THE MID ATLANTIC GRUDGINGLY HANGS ON. GRADIENT IS WEAK HOWEVER AND WIND SPEEDS WILL REMAIN BELOW 10 KNOTS. WITH LITTLE TROPICAL ACTIVITY IN THE OPEN ATLANTIC...SIGNIFICANT WAVE HEIGHTS WILL REMAIN LOW IN A 2-3 FOOT RANGE WITH THE SPECTRUM ALMOST EXCLUSIVELY WIND WAVES. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...SHK NEAR TERM...REK SHORT TERM...SHK LONG TERM...SHK AVIATION...JDW US Dept of Commerce National Oceanic and Atmospheric Administration National Weather Service 1325 East West Highway Silver Spring, MD 20910 Page Author: NWS Internet Services Team Disclaimer Information Quality Credits Glossary Privacy Policy Freedom of Information Act (FOIA) About Us Career Opportunities
Powered by HAMweather
Racing Gear and other Stuff
Powered byIP2Location.com
