Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 051832 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 232 PM EDT TUE MAY 5 2015 .SYNOPSIS... HIGH PRESSURE WILL REMAIN WELL OFF THE SOUTHEAST AND MID ATLANTIC COAST THROUGH THIS EVENING...BRINGING VERY WARM AND MAINLY DRY CONDITIONS TO THE LOCAL AREA. A BACKDOOR COLD FRONT APPROACHES FROM THE NORTH TONIGHT...THEN DROPS INTO VIRGINIA LATE WEDNESDAY INTO EARLY THURSDAY...BEFORE DISSIPATING. LOW PRESSURE WILL SPIN OFF OR NEAR THE SOUTHEAST COAST THURSDAY INTO SATURDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST ANALYSIS REVEALS SFC HIGH PRESSURE CENTERED WELL OFFSHORE OF THE VA/NC COAST, EXTENDING BACK ACROSS EASTERN NC. ~1006 MB LOW PRESSURE WAS ANALYZED ACROSS NEWFOUNDLAND, WITH SFC COLD FRONT SNAKING BACK ACROSS NEW ENGLAND INTO N PA AND THE EASTERN GRT LAKES. A PRE-FRONTAL SFC TROUGH EXTENDS SW FROM SOUTHEASTERN NEW ENGLAND, METRO NYC AND INTO SRN MD AND NORTHERN VA. FOR TODAY...OFF TO A MILD START ACROSS THE LOCAL AREA, WITH TEMPERATURES LARGELY IN THE MID TO UPPER 70S, WITH SOME UPPER 70S ALONG THE EASTERN SHORE OF THE CHES BAY IN SSW FLOW. A VERY WARM DAY IS EXPECTED THROUGHOUT THE CWA. LOOKING FOR HIGHS ABOUT 10 DEGREES ABOVE AVG...INTO THE MIDDLE TO POSSIBLY UPPER 80S OVER CENTRAL AND SOUTH CENTRAL VA...TO 80-85 F MOST OTHER PLACES (LOCALLY A LITTLE COOLER IN THE 70S ALONG THE IMMEDIATE COAST AND ADJACENT TO THE BAY AS FLOW BACKS MORE TO THE SSE IN THE AFTN). SHOULD BE SUNNY TO MOSTLY SUNNY THROUGH MIDDAY...WITH INCREASING AFTN CU ALONG THE MTNS TO THE WEST AND EVENTUALLY ALONG THE TROUGH BY EARLY TO MID AFTN. DO HAVE SOME LOW CHANCES FOR SHOWERS/TSTMS ACRS THE FAR N/NW AFTER ABOUT 20-21Z. FLOW ALOFT IS QUASI-ZONAL AND SHOULD THEREFORE ALLOW FOR A VERY SLOW SOUTHWARD PROGRESSION OF THE FRONT. HOWEVER, BY THIS EVENING SHORTWAVE ENERGY ACRS THE GRT LAKES BEGINS TO DIVE MORE TO SE...AND UPPER FLOW TURNS MORE TO THE WNW. THIS WOULD FAVOR STORMS OVER FAR NRN AREAS...MOVING A BIT FARTHER TO THE SOUTH ESPECIALLY IF ENOUGH CONVECTIVE DEVELOPMENT OCCURS WITH OUTFLOWS RACING OUT AHEAD TO THE SE. THIS APPEARS MOST LIKELY FOR THE ERN SHORE...AND HAVE RAISED POPS A LITTLE HIGHER THERE AS WELL AS OVER THE NRN NECK/MIDDLE PENINSULA...KEPT IT OUT OF HAMPTON ROADS FOR NOW. FARTHER SW EXPECT DRY CONDS/PARTLY CLOUDY SKIES. STRONG TO SEVERE STORMS APPEAR UNLIKELY AS STRONGER SHEAR PROFILES LOOK TO STAY N...AND TIMING WOULD BE MAINLY AFTER DARK. LOWS TONIGHT IN THE UPPER 50S TO LWR 60S. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... SLGT CHC (20%) WILL CONTINUE OVR NE COUNTIES EARLY WED MORNG...DUE TO LINGERING MOISTURE/LIFT SLIDING ESE ALNG BACKDOOR FRONT. OTHERWISE...LATER IN THE DAY WED THE FRONT WILL DROP INTO VA BEFORE DISSIPATING...WHILE WEAK HI PRES BLDS IN BEHIND IT...THEN SLIDES OFF THE NRN MID ATLC CST. AT THE SAME TIME...LO PRES WILL LIFT NWRD OFF THE FL AND SE CST. HEATING COMBINED WITH WEAK CONVERGENCE AND SOME LIFT ALNG THE FRONTAL BOUNDARY...MAY TRIGGER ISLTD TO SCTD SHOWERS OR TSTMS...MAINLY OVR WRN AND NRN COUNTIES WED AFTN INTO WED EVENG. PARTLY TO MOSTLY SUNNY WITH HIGH TEMPS RANGING FM 80-85 F W OF THE BAY...TO THE 70S ON THE ERN SHORE. GENLY FAVOR THE NAM/ECMWF SOLN OVER THE FASTER GFS WITH RESPECT TO WINDS...SO HIGH TEMPS ARE ON THE WARM SIDE OF GUIDANCE MOST AREAS. SLOWER PROGRESSION OF FRONT THU YIELDS MORE CLOUDS THAN PREV FORECAST FOR NRN AREAS IN THE MORNING. GENERALLY PARTLY SUNNY FARTHER SOUTH A 20-30% CHC FOR A SHOWER OR TSTM MAINLY IN THE AFTN. NE OR E WINDS WILL RESULT IN HI TEMPS RANGING THRU THE 70S TO NEAR 80 SW TO THE UPPER 60S/LWR 70S ERN SHORE. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... MEDIUM RANGE PERIOD HIGHLY DEPENDENT PERSISTENT UPPER RIDGE OVER THE EAST, AS WELL AS THE DEVELOPMENT AND EVENTUAL PROGRESS OF EXPECTED DEVELOPMENT OF AN AREA OF LOW PRESSURE OFF THE EAST COAST OF FLORIDA. MODELS ARE IN GENERAL AGREEMENT OF THE DEVELOPMENT AND INITIAL SLOW DRIFT NORTHWARD ON WEDNESDAY. THE HURRICANE CENTER IS CONTINUING TO MONITOR THIS FEATURE FOR POTENTIAL SUBTROPICAL DEVELOPMENT. SFC RIDGING TO THE NORTH AND W-NW FLOW ALOFT SHOULD FORCE THE LOW TO MEANDER AROUND A POSITION ALONG/JUST OFF THE SOUTHEAST COAST THROUGH THE WEEKEND. THE GEFS AND EURO ENSEMBLES BOTH CONTINUE TO TAKE THE LOW INLAND ALONG THE SC/GA COAST, AS DOES THE NEW 12Z/04 GFS. THE OPERATIONAL EUROPEAN, MEANWHILE CONTINUES TO KEEP THE SYSTEM OFFSHORE. A SOLUTION TOWARDS THE GFS REMAINS THE HPC PREFERENCE, AND HV EDGED THE FORECAST IN THIS DIRECTION. THIS SCENARIO WOULD YIELD SLIGHT CHC TO LOW CHC POP FOR MAINLY DIURNALLY DRIVEN SHOWERS/T-STORMS AT MOST ACROSS OUR AREA. LOWEST CHANCES WILL BE ACROSS THE NORTH WITH SFC RIDGING IN PLACE NORTH OF THE AREA. OTHER HEADLINE FOR THE PERIOD WILL BE THE WARMER TEMPERATURES. E-SE FLOW WILL BRING A MODEST INCREASE IN HUMIDITY, AND INCREASING LOW LEVEL THICKNESSES FAVOR WARM HIGHS IN THE 80S UNDER A PARTLY TO MOSTLY SUNNY SKY. EARLY MORNING LOWS LOOK TO REMAIN WELL INTO THE 50S TO MID 60S LATE WEEK INTO EARLY NEXT WEEK. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... HIGH PRESSURE GENERALLY IN CONTROL OVER THE MID-ATLANTIC THIS AFTERNOON WITH A WEAK SURFACE TROUGH TO THE NORTH OF THE AKQ CWA. A COLD FRONT REMAINS OVER SOUTHERN NY STRETCHING WEST INTO PA AND OH. SWLY WINDS 10-15 KT CONTINUE WITH A FEW AFTERNOON GUSTS AROUND 20 KT. SHOWERS/THUNDERSTORMS DEVELOP ALONG THE FRONT LATE TODAY...DROPPING SWD TOWARD THE NRN LOCAL AREA TONIGHT. WILL LIKELY SEE AN INCREASE IN MID-HIGH CLOUDS EARLY TONIGHT AT KSBY AND KRIC...WITH SHOWERS (POSSIBLY A THUNDERSTORM) POSSIBLE LATE TONIGHT AT KSBY. OUTLOOK: THERE WILL BE A DAILY CHANCE FOR MAINLY AFTN AND EARLY EVENING SHOWERS AND THUNDERSTORMS WEDNESDAY THROUGH SATURDAY. THEY ARE NOT EXPECTED TO BE WIDESPREAD. OTHERWISE MAINLY VFR CONDITIONS ARE EXPECTED DURING THE PERIOD. LATE IN THE WEEK...PATCHY FOG WILL BE PSBL AROUND SUNRISE. && .MARINE... LATEST WEATHER ANALYSIS ACROSS THE WATERS DEPICTS HIGH PRESSURE CENTERED ROUGHLY 500 NM OFF THE MID ATLANTIC COAST AND LOW PRESSURE OVER NEWFOUNDLAND. AN ATTENDANT COLD FRONT EXTENDS FROM THE SFC LOW SWWD INTO NEW ENGLAND AND THE OH VALLEY. GRADIENT HAS RESULTED IN A PERIOD OF MARGINAL SCA CONDITIONS OVER THE BAY AND LOWER JAMES RIVER EARLY THIS MORNING...WITH OCCASIONAL GUSTS 20-25 KT. HAVE OPTED TO ISSUE SCA HEADLINES THRU 7 AM AS GRADIENT EXPECTED TO RELAX AND LOW LEVELS STABILIZE. WAVES GENERALLY 2-3 FT AND SEAS AROUND 3 FT. HIGH PRESSURE PUSHES FARTHER OFFSHORE TODAY AS THE COLD FRONT SLOWLY APPROACHES FROM THE NORTH. S-SW WINDS GENERALLY 10-15 KT TODAY...WITH OCCASIONAL GUSTS TO 20 KT IN THE COASTAL WATERS. SLIGHT UPTICK IN WINDS POSSIBLE AGAIN TONIGHT...BUT NOT AS STRONG AS EARLY THIS MORNING AS THE WINDS ALOFT ARE PROGGED TO BE WEAKER. THE COLD FRONT IS PROGGED TO REACH THE NRN WATERS LATE WEDS...DROPPING ACROSS THE WATERS WEDS NIGHT INTO THURS. THE FRONT THEN WASHES OUT OVER THE REGION THURS AS LOW PRESSURE LOCATES OFF THE SE COAST. FLOW BEHIND THE FRONT BECOMES NELY...REMAINING AOB 15 KT. SEAS ONLY PROGGED TO BUILD TO 3-4 FT WEDS NIGHT-THURS. UNCERTAINTY STILL EXISTS IN THE EXACT TRACK AND STRENGTH OF THE COASTAL LOW LATE IN THE WEEK. ATTM...MODELS KEEP THE LOW OFF THE SE COAST INTO THE WEEKEND. THIS TRACK STAYS TOO FAR SOUTH TO BRING ANY SIGNIFICANT INCREASE IN SEAS AND WINDS TO THE LOCAL AREA. OTHERWISE...HIGH PRESSURE REMAINS OVER THE LOCAL WATERS THRU THE WEEKEND WITH SE WINDS GENERALLY AOB 15 KT. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM NEAR TERM...LKB/MAM SHORT TERM...LKB/TMG LONG TERM...MAM AVIATION...SAM/DAP MARINE...MAM/SAM

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