Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 211949 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 349 PM EDT THU MAY 21 2015 .SYNOPSIS... LOW PRESSURE PUSHES OFF THE NORTH CAROLINA COAST THIS EVENING...THEN LIFTS NORTHEAST WELL OFF THE MID-ATLANTIC COAST TONIGHT. HIGH PRESSURE WILL BUILD ACROSS THE AREA FRIDAY INTO SATURDAY...BEFORE SLIDING OFF THE COAST SUNDAY INTO EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... SFC LOW PRESSURE WAS LOCATED OVER SE NC AS OF 330 PM...WITH A WARM FRONT DRAPED ACROSS NE NC JUST NORTH OF THE ALBEMARLE SOUND. THIS SYSTEM HAS BROUGHT MUCH-NEEDED RAIN TO MUCH THE AREA TODAY...WITH AMOUNTS RANGING FROM 0.25-1.00" (LOWEST NW). AS THE SFC LOW CONTINUES TO MOVE EAST THROUGH EARLY EVENING...WILL SEE TSTMS MOVE ACROSS FAR SE VA AND NE NC NEAR OR JUST SOUTH OF THE WARM FRONT. A SVR TSTM WATCH REMAINS IN EFFECT SOUTH OF THE ALBEMARLE UNTIL 8 PM...BUT CANNOT COMPLETELY RULE OUT AN ISOLD STRONG TO SVR STORM OR TWO SKIRTING THE NORTH SIDE OF THE ALBEMARLE SOUND THE NEXT FEW HOURS. NORTH OF THE WARM FRONT...A CLOUDY/COOL/WEDGE SCENARIO IS EXPECTED TO REMAIN IN PLACE LATE THIS AFTN/EVE UNTIL PCPN EXITS THE COAST BY LATER THIS EVENING. HAVE ALREADY SEEN PCPN COME TO AN END ACROSS THE PIEDMONT THIS AFTERNOON...AND IT SHOULD BE OVER ALONG THE I-95 CORRIDOR BETWEEN 4-5 PM. THE SFC LOW EXITS THE NC COAST AROUND 00Z THEN MOVES FARTHER OFFSHORE OVERNIGHT...RESULTING IN A GRADUAL DECREASE IN CLOUDS. PCPN SHOULD BE OVER BEFORE MIDNIGHT ALONG THE COAST. LOW TEMPS WILL RANGE FROM THE UPR 40S NW TO THE UPR 50S SE. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/... SFC HIGH PRESSURE TO THE WNW PREVAILS FOR MUCH OF FRI...ALLOWING FOR SUNSHINE AND COMFORTABLE TEMPS. HIGHS MAINLY IN THE 70S. HOWEVER...THE MODELS DO SHOW A SECONDARY COLD FRONT APPROACHING FROM THE NORTH LATE FRI...AND PASSING THRU THE AREA FRI EVE/NIGHT. MODELS ARE NOT AS BULLISH ON PRODUCING ISOLD SHOWERS WITH THE FRONT ACROSS THE NRN NECK/ERN SHORE...SO HAVE REMOVED THEM FROM THE FORECAST. THE FRONT WILL HOWEVER PRODUCE SOME CLOUDS...ACROSS MAINLY THE NRN NECK AND ERN SHORE. LOWS WILL RANGE FROM THE UPR 40S NW TO THE MID TO UPR 50S SE. BY SAT...COOL HIGH PRESSURE SETTLES OVER THE MID-ATLANTIC REGION. SUNSHINE IS EXPECTED WITH NORTH WINDS BECOMING ONSHORE LATE IN THE DAY HELPING TO KEEP MAX TEMPS IN CHECK. HIGHS 70-75 INLAND/PIEDMONT...AND IN THE MID TO UPR 60S NEAR THE WATER. THE SFC HIGH SHIFTS OFFSHORE SUNDAY FOR CONTINUED DRY WX. HIGH TEMPS WILL WARM BACK INTO THE UPR 70S/LOW 80S WITH SOUTHERLY RETURN FLOW. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... MEDIUM RANGE BEGINS WITH LATEST GFS/ECMWF REMAINING INTO GOOD AGREEMENT WITH UPPER LEVEL RIDGE CENTERED OVER FLORIDA ON SUN...BUILDING BACK NORTH INTO THE MID ATLC STATES MON/TUE. THE GFS TRIES TO FLATTEN/BREAK THE RIDGE DOWN LATE TUE INTO WED AS IT IS WEAKER WITH THE UPPER LEVEL TROUGH FROM THE DESRT SW TO THE SRN/CENTRAL PLAINS. ECMWF IS GENLY PREFERRED AT THIS TIME GIVEN THE BUILDING RIDGE OVER THE SE CONUS. THIS PATTERN WILL LEAD TO A WARMING TREND BEGINNING ON SUN...AS FLOW TURNS AROUND TO THE SSW WITH SFC HIGH PUSHING WELL OFFSHORE. A WEAK WARM FRONT STILL PROGGED TO LIFT N THROUGH THE OHIO VALLEY AND NRN MID ATLC REGION LATE SUN AFTN/SUN NIGHT...BUT BULK OF PRECIP SHOULD STAY OFF TO OUR N. WILL MAINTAIN A 20% POP ACRS THE FAR NE PORTIONS OF THE CWA TO ACCOUNT FOR THIS...BUT WILL MAINTAIN A DRY FORECAST ELSEWHERE UNDER PARTLY CLOUDY SKIES. HIGHS RISE INTO THE LWR 80S INLAND AND IN THE 70S CLOSER TO THE COAST. FROM MON-WED...500 MB HEIGHTS RISE AND BULK OF TSTM ACTIVITY SHOULD CONTINUE TO STAY OFF TO OUR NORTH. WILL KEEP A LATE AFTN/EVENING 20% POP OVER MAINLY THE NRN PORTIONS OF THE CWA ON MON...AND GENLY A 20% POP IN THE LATE AFTN/EVENING OVER MUCH OF THE AREA TUE/WED. IF GFS ENDS UP BEING CORRECT...POPS FOR WED WILL NEED TO BE RAISED. SUMMERLIKE WX RETURNS WITH INCREASING HUMIDITY AND HIGH TEMPS WARMING BACK TO 85-90 F MON...AND UPPER 80S TO LWR 90S TUE/WED. CONDITIONS WILL GENLY BE ABOUT 5 DEGREES COOLER AT THE COAST. && .AVIATION /19Z THURSDAY THROUGH TUESDAY/... SHWRS AHEAD OF APPRCHG LOW PRESSURE FROM THE SW RESULTING IN BOTH SPORATIC IFR CIGS AND VSBYS THIS AFTRN AT RIC/PHF WHILE SBY/ORF/ECG REMAIN AT VFR. THE SHWRS WILL CONTINUE ACROSS THE PIEDMONT THRU ABT 21Z OR SO THEN TAPER OFF AS THE BEST MOISTURE PUSHES TOWARDS THE COAST. SHWRS WILL CONTINUE TO PRODUCE LCL IFR/MVFR CNDTNS AT SBY/PHF/ORF THRU ABT 00Z. A WARM FRONT IS LIFTING NORT ACROSS THE NORTH CAROLINA COASTAL PLAIN ATTM. THIS BNDRY IS PROGGED TO LIFT NORTH TO A POSITION IVOF THE ALBEMARLE SOUND BY 21Z. MEANWHILE...BAND OF CONVECTION IS MOVING EAST ACROSS SRN VA/NRN NC THIS AFTRN. THIS CONVECTION IS EXPECTED TO INCREASE IN INTENSITY NEXT FEW HOURS. THUS...CONFIDENCE HIGH ENOUGH TO INCLUDE A 2 HOUR TEMPO TSTRM GROUP AT ECG (20-22Z) GIVEN THE LINES CURRENT SPEED. LOW PRESSURE AND ASSCTD FRONTAL BNDRYS WILL MOVE OFFSHORE THIS EVENING WITH ALL DATA SUPPORTING MUCH DRIER AIR BEHIND THE SYSTM AFTER MIDNIGHT. GFS SUGGESTS PSBLTY OF IFR FOG IN SOME PLACES LATE TONIGHT BU CONFIDENCE NOT HIGH ENOUGH TO PUT INTO THE FCST ATTM. VFR CNDTNS FRI AND INTO THE WKEND AS HIGH PRS BUILDS INTO THE AREA. && .MARINE... PRESSURE GRADIENT TIGHTENING AS LOW PRESSURE APPRCHS FROM THE SE. WINDS ACROSS THE CHES BAY HAVE INCREASED WITH NMRS GUSTS TO 20 KTS REPORTED ERLY THIS AFTRN. THUS...HAVE INCREASED WIND SPEEDS TO ACCOUNT FOR THE CRNT CNDTNS. PRVS DSCN: LATEST CONDITIONS REFLECT E-NE FLOW ACROSS THE WATERS THIS MORNING AVERAGING 10-15KT. LATEST ANALYSIS FEATURES AN AREA OF SFC LOW PRESSURE INLAND OF THE COASTAL CAROLINAS, WITH AN ASSOCIATED WAVY FRONTAL BOUNDARY EXTENDING BACK INTO THE MID-SOUTH AND DEEP SOUTH. MODELS HAVE COME INTO BETTER AGREEMENT WITH THE EVOLUTION OF THIS SYSTEM OVER THE NEXT 24-36 HOURS. APPEARS THAT SFC LOW WILL PUSH NE ALONG THE NC COASTAL PLAIN, PUSHING OFFSHORE AND JUST SOUTHEAST OF THE LOCAL AREA LATE TONIGHT/OVERNIGHT. QUICK TIGHTENING OF SFC PG, A RESULT OF STRONG 6-HR PRESSURE RISES ON THE ORDER OF 6-8 MB ON THE BACK SIDE OF THE SYSTEM AS IT RAPIDLY INTENSIFIES OFF THE COAST TONIGHT, SHOULD ALLOW FOR ONSHORE WINDS TO QUICKLY BACK TO THE NNW. A STRONG SCA SURGE OF WIND WL ACCOMPANY THE WIND SHIFT. SMALL CRAFT ADVISORIES NOW GO INTO PLACE AT NOON FOR THE BAY AND LOWER JAMES, MAINLY TO ENCOMPASS E-SE FLOW AHEAD OF THE SYSTEM EARLY THIS AFTN BEFORE WINDS BACK TO THE NNE BEHIND THE SYSTEM TONIGHT. FOR THE UPPER BAY, BEST SURGE OF WINDS LOOKS TO BE DELAYED UNTIL EARLY THIS EVENING. SCA HEADLINES ARE ALSO NOW IN PLACE FOR THE CURRITUCK SOUND (STARTING @ 1 PM) AND COASTAL ZONES (STARTING TONIGHT). CONDITIONS IMPROVE THROUGH THE DAY ON FRI AS LOW PRESSURE SYSTEM QUICKLY SCOOTS TOWARD THE CANADIAN MARITIMES BY FRIDAY NIGHT. ANOTHER BRIEF NORTHERLY SURGE EXPECTED FRIDAY NIGHT AS COOL ~1030 MB HIGH PRESSURE BUILDS IN FROM THE N. THE POTENTIAL FOR ADDITIONAL HEADLINES BEING NEEDED EXISTS WITH THE ASSOCIATED SFC COLD FRONT AS IT DROPS ACROSS THE AREA FRI NIGHT. THE HIGH SHIFTS OFF THE COAST FOR THE LATTER HALF OF THE HOLIDAY WEEKEND WITH THE RESULTANT SFC FLOW BACKING TO THE S/SE, AVGG AOB 15 KT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT FRIDAY FOR ANZ630>632-634. SMALL CRAFT ADVISORY UNTIL 7 AM EDT FRIDAY FOR ANZ633-638. SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 7 AM EDT FRIDAY FOR ANZ650-652-654-656-658. && $$ SYNOPSIS...JDM NEAR TERM...JDM SHORT TERM...JDM/TMG LONG TERM...LKB AVIATION...MPR MARINE...LKB

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