Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 211600 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1200 PM EDT THU MAY 21 2015 .SYNOPSIS... LOW PRESSURE WILL TRACK EAST ACROSS THE CAROLINAS TODAY...THEN LIFTS NORTHEAST OFF THE MID ATLANTIC COAST AND OUT TO SEA TONIGHT INTO EARLY FRIDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE AREA AND OFF THE COAST FRIDAY THROUGH SUNDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 11 AM...SFC LOW PRESSURE WAS OVER SOUTH-CENTRAL NC. A WARM FRONT STRETCHED FROM THE CENTRAL OBX TO THE LOW CENTER....WHILE AN INVERTED TROUGH EXTENDED NORTHWARD INTO THE MOUNTAINS. THE SFC LOW WILL CONTINUE TO MOVE EASTWARD TODAY...REACHING ERN NC BETWEEN 18Z-21Z...THEN MOVING NE OFF THE MID COAST THIS EVE AND TONIGHT. S/W ENERGY APPROACHING FROM THE WEST WILL HELP DEEPEN/INTENSIFY THE LOW SOMEWHAT...AS IT PASSES THRU SE VA/NE NC THIS AFTN/EVE. A COOL/WEDGE SCENARIO IS ALREADY IN PLACE THIS MORNING NORTH OF THE LOW AND HAVE SEEN MUCH NEEDED RAIN FALLING OVER VA/MD WITH TEMPS IN THE 50S TO LOW 60S. ALONG/S OF THE SFC LOW/FRONTAL BOUNDARY...S-SE WINDS WILL BRING A SURGE OF WARM/UNSTABLE AIR INTO SE VA/NE NC THIS AFTN INTO EARLY THIS EVE. THE RESULT WILL BE QUITE A TEMP CONTRAST FM NW TO SE...WITH HIGHS IN THE UPR 50S/LWR 60S NW AND IN THE MID TO UPR 70S ACROSS NE NC. TEMPS ACROSS THE N-NW HALF OF THE FA SHOULD ACTUALLY HOLD STEADY TODAY....WITH STEADY OR SLOWLY FALLING TEMPS ALONG THE I-95 CORRIDOR THIS AFTN. ACROSS THE SE (WHERE WARMER/MORE UNSTABLE AIR WILL BE IN PLACE)...THERE WILL BE A POSSIBILITY OF TSTMS THIS AFTN. SPC CURRENTLY HAS AREAS ALONG/S OF THE ALBEMARLE SOUND IN A SLIGHT RISK FOR SVR WX. DEPENDING ON THE EVENTUAL TRACK OF THE SFC LOW AND HOW MUCH SUN PEEKS THRU...THE CLOUDS WILL DETERMINE WHETHER OR NOT A STRONGER STORM IS ABLE TO DEVELOP OVER NE NC. TOTAL QPF AMOUNTS WILL BE ON THE ORDER OF 0.25-0.75" WITH THIS SYSTEM. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... THE SFC LO MOVES FARTHER OFFSHORE TNGT...RESULTING IN A GRADUAL DECREASE IN CLOUDS/POPS. LOW TEMPS WILL RANGE FM THE UPR 40S NW TO THE UPR 50S SE. SFC HI PRES TO THE WNW PREVAILS FOR MUCH OF FRI...ALLOWING FOR SUNSHINE AND COMFORTABLE TEMPS. HIGHS WILL RANGE THRU THE 70S. HOWEVER...THE MODELS DO SHOW A SECONDARY COLD FRONT APPROACHING FM THE N LATE FRI...AND PASSING THRU THE AREA FRI EVENG/NGT. THIS FRONT WILL JUST PRODUCE SOME CLOUDS...ACRS MAINLY THE NRN NECK AND ERN SHORE. LOWS WILL RANGE FM THE UPR 40S NW TO THE MID TO UPR 50S SE. BY SAT...COOL HI PRES SETTLES OVER THE MID-ATLC REGION. SUNSHINE IS EXPECTED WITH N 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. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... 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 /16Z THURSDAY THROUGH MONDAY/... VFR CONDITIONS STILL HANGING ON AT AREAL TERMINALS AT 12Z. HOWEVER, STILL EXPECTING GRADUAL DETERIORATION OF CONDITIONS OVER THE NEXT FEW HOURS AHEAD OF AN APPROACHING LOW PRES SYSTEM. CIGS LOOK TO DIMINISH FIRST AT RIC/PHF...AND BY MID TO LATE MORNING AT SBY/ORF/ECG. EXPECT A BRIEF PERIOD OF (TEMPO?) IFR CONDITIONS THIS AFTERNOON INTO TONIGHT AS THE WAVE OF LOW PRESSURE SLIDES ACROSS NC AND BRIEFLY PULLS A WARM FRONT NORTH OF THE VA TIDEWATER AREA THIS AFTERNOON. CONSIDERED VICINITY THUNDER/CB WORDING AT ECG, WITH SCT TSTORMS POSSIBLE AS WARM FRONT LIFTS NORTH AHEAD OF THE SYSTEM. HOWEVER, HIGH-RES MODEL DATA SHOWING BEST INSTABILITY JUST TO THE SOUTH OF THE TERMINAL. WILL THEREFORE HOLD OUT OF THE TAF FOR NOW. THE LOW PRESSURE AREA WILL CLEAR THE COAST AFTER 00Z FRI AND WITH COOL HIGH PRESSURE BUILDING INTO THE AREA...RETURN THE REGION TO VFR CONDITIONS TONIGHT THROUGH EARLY FRIDAY MORNING. OUTLOOK...HIGH PRESSURE WILL REBUILD OVER THE REGION FRIDAY THROUGH THE WEEKEND. VFR CONDITIONS ARE EXPECTED FOR THE HOLIDAY WEEKEND. && .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...TMG NEAR TERM...JDM/TMG SHORT TERM...JDM/TMG LONG TERM...LKB AVIATION...MAM MARINE...MPR/MAM

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