Area Forecast Discussion
Issued by NWS Wakefield, VA

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045 FXUS61 KAKQ 091852 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 152 PM EST TUE FEB 9 2016 .SYNOPSIS... AN AREA OF LOW PRESSURE DEEPENS WELL OFF THE MID ATLANTIC COAST TODAY AS AN UPPER LEVEL TROUGH SWINGS THROUGH THE REGION LATER THIS THROUGH TONIGHT. HIGH PRESSURE SLOWLY RETURNS WEDNESDAY THROUGH FRIDAY. && .NEAR TERM /THROUGH TONIGHT/... LATEST GOES WATER VAPOR IMAGERY DEPICTS MERIDIONAL FLOW OVER THE CONUS...HIGHLIGHTED BY AN ANOMALOUS RIDGE IN THE WEST AND ANOMALOUS TROUGH (-2 TO -3 STD DEV) IN THE EAST. AT THE SFC...~995MB LOW PRESSURE IS CENTERED ROUGHLY 300 MILES DUE EAST OF THE VACAPES WITH ANOTHER AREA OF LOW PRESSURE OVER THE GREAT LAKES REGION. HIGH PRESSURE ALSO LOCATED OVER NEW ENGLAND...WITH A COL/WEAK SFC TROUGHING OVER THE NRN MID ATLANTIC REGION. LATEST REGIONAL MOSAIC MATCHES UP WELL WITH THE ADDED LOW LEVEL FORCING ALONG THE SFC TROUGH...LINGERING ONLY OVER THE ERN SHORE. THE OFFSHORE SYSTEM IS PROGGED TO CONTINUE TO INTENSIFY TODAY...BUT WILL RAPIDLY MOVE FARTHER OUT TO SEA. AS THE UPPER LOW DRIFTS EAST LATER TODAY AND THIS EVENING...SHORTWAVE ENERGY WILL HELP DEVELOP A WEAK SFC LOW PER THE 00Z GFS/NAM ACRS MD/NRN VA AND PUSH OFF THE DELMARVA THIS EVENING. OVERALL TRENDS IN THE MODELS CONTINUE TO BE WARMER/SLOWER TO WRAP THE COLD AIR INTO THE REGION FROM THE NW. BOUNDARY LAYER FLOW LOOKS TO BE WEST OR EVEN WSW TODAY...AND THIS WILL KEEP DEEPER MOISTURE NORTH OF MOST OF THE CWA AND SHOULD PROMOTE SOME LATE MORNING THROUGH MID AFTN SUNSHINE FOR ALL BUT THE NORTH. WITH THIS IN MIND...CONTINUED THE TREND OF INCREASING TEMPS CLOSER TO MAV/MET GUIDANCE BUT REMAINING ON THE COLD SIDE. HIGHS GENERALLY IN THE UPPER 40S ACRS FAR SE VA/NE NC...TO THE LOWER 40S ACRS THE NORTHERN ZONES. AS FOR POPS...WILL HAVE CHC A CONFINED TO THE NORTH LATER THIS MORNING...THEN RAISE POPS TO LOW END LIKELY NE LATER IN THE AFTN AS THE UPPER ENERGY ARRIVES...TAPERED TO 20-30% FARTHER SOUTH. STILL ONLY RAIN OR A MIX THROUGH MID AFTN...TRENDING COLDER LATE. BY THIS EVENING...COLDER AIR WILL OVERSPREAD THE CWA AS CRITICAL THICKNESSES DROP WELL BELOW 1300 M. OVERALL THOUGH...TRENDS ARE WEAKER IN THE MODELS WITH RESPECT TO FORCING AND DEEP MOISTURE...NOW PROGGED TO STAY PRIMARILY NORTH OF THE CWA. STILL ANTICIPATE A 3-6 HR WINDOW FOR SCATTERED SNOW SHOWERS ACRS THE NRN NECK/ERN SHORE...BUT ACCUMULATIONS ARE EXPECTED TO BE UP TO 1" AT MOST (GENERALLY LITTLE TO NO ACCUMULATION FOR THE REST OF THE CWA). LOWS M20S WEST TO LOWER 30S ALONG THE COAST. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... A DEEP UPPER LEVEL TROUGH PREVAILS ACROSS THE ERN CONUS ON WED AS A STRONG RIDGE PERSISTS ALONG THE WEST COAST. OVERALL...SHOULD HAVE DRIER AIR IN PLACE ACROSS THE REGION WITH DECENT SUBSIDENCE PRESENT IN THE WAKE OF THE EXITING SHORTWAVE LOCATED WELL TO THE NORTHEAST. STEEP LAPSE RATES STILL PRESENT DUE TO THE COLD POOL ALOFT SO EXPECT PARTLY SUNNY/VARIABLY CLOUDY CONDITIONS. KEPT 20 PERCENT POPS FOR SNOW SHOWERS ACROSS NERN AREAS THRU THE MORNING HRS. OTW...PT SUNNY AND COLD. HIGHS U30S NORTH TO L40S SOUTH. MAINLY DRY AND COLD WED NIGHT WITH LOWS FALLING INTO THE TEENS WEST TO THE 20S ELSEWHERE. AS COLDER AIR SPILLS IN...COULD SEE A FEW BAY ENHANCED SNOW SHOWERS ACRS MAINLY THE VA ERN SHORE SO WILL CARRY 20-30% POPS THERE. COLDER BUT MOSTLY SUNNY ON THU (PARTLY SUNNY ERN SHORE) WITH HIGHS IN THE LOWER 30S NORTH TO THE MID- UPPER 30S SOUTH. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... AN UPPER LEVEL LOW PRESSURE SYSTEM WILL HEAD NORTHEAST AND AWAY FROM THE EASTERN CONUS WEDNESDAY INTO THURSDAY...ONLY TO BE REPLACED BY A STRONG UPPER LEVEL TROUGH LATE FRIDAY INTO THE COMING WEEKEND. PCPN CHANCES WILL BE LIMITED THROUGH THE PERIOD... ALTHOUGH A ROUND OF SNOW SHOWERS IS POSSIBLE ON FRIDAY WITH AN ARCTIC FRONTAL PASSAGE. BAY/OCEAN EFFECT SNOW SHOWERS ALONG THE COAST WILL BE POSSIBLE SATURDAY AND SUNDAY AS VERY COLD AIR ALOFT (-20 TO -25 H85 TEMPS) SETTLE IN. ALTHOUGH A LOW CONFIDENCE FORECAST ATTM...THERE ARE SOME INDICATIONS THAT LOW PRESSURE DEVELOPS ALONG THE CAROLINA COAST FRI/FRI NIGHT WHICH COULD PROVIDE ADDITIONAL MOISTURE FOR THE ARCTIC FRONT TO WORK WITH. IF THIS ENDS UP BEING THE CASE...THEN ACCUMULATING SNOW WOULD BE POSSIBLE ACROSS A PORTION OF THE AREA LATE IN THE WEEK. OF MORE SIGNIFICANCE ATTM IS THE VERY COLD AIR SETTLING OVER THE REGION BY THE WEEKEND. HIGHS IN THE 30S THU- SAT...BUT THEN ONLY 20S TO MAYBE LOW 30S SUNDAY. LOWS TEMPS IN THE TEENS AND 20S...WITH SINGLE DIGITS SATURDAY NIGHT. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... SFC LO PRES DEVELOPS OFF THE DELMARVA CST THIS AFTN WITH ANOTHER AREA OF LO PRES OVER THE ERN GREAT LAKES REGION. BETWEEN THESE TWO FEATURES...BKN-OVC SKIES ARE COMMONPLACE OVER THE FA WITH MAINLY VFR CONDS WITH THE EXCEPTION OF KSBY WHERE MVFR CIGS ARE CONTINUING THIS AFTN. PREVAILED -RA THERE WITH A TEMPO GROUP INCLUDED FOR A RA/SN MIX LATER THIS AFTN AS COLDER TEMPS ALOFT MAY HELP CHANGEOVER THE PCPN. ELSEWHERE...VFR CONDS EXPECTED FOR THE DURATION OF THE TAF PERIOD WITH A CHANCE OF -RA THIS AFTN AT KRIC. WINDS REMAIN WLY AVGG 8-12 KT. OUTLOOK...VFR CONDITIONS SHOULD PREVAIL WED NGT THRU FRI...AS HI PRES BLDS INTO THE MID ATLC REGION. && .MARINE...
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LO PRES CONTINUES TO DEVELOPE WELL E OF THE VA/NC CST. THAT LOW WILL MOVE QUICKLY AWAY TO THE NE TODAY INTO TNGT...RESULTING IN WINDS SHIFTING TO THE W AND INCREASING TO 15 TO 20 KT OVR MOST OF THE MARINE AREA. HOWEVER...W WINDS WILL INCREASE TO 20 TO 25 KT WITH GUSTS TO ARND 30 KT EXPECTED OVR THE SRN CSTL ZNS TNGT. SEAS WERE STILL BETWEEN 6 AND 10 FT EARLY THIS AFTN...AND WILL CONTINUE TO SUBSIDE INTO TNGT DUE TO OFFSHR W WINDS. ANOTHER ROUND OF SCA CONDITIONS APPEAR LIKELY FOR THE ENTIRE MARINE AREA TUE NIGHT INTO THU NGT...AS STRONG NW WINDS ARE EXPECTED. GALE CONDITIONS MAY BE POSSIBLE BY THE WEEKEND...AS SOME VERY COLD AIR SETTLES OVER THE MARINE AREA.
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&& .HYDROLOGY... RIVER FLOOD WARNINGS REMAIN IN EFFECT FOR THE BLACKWATER ABOVE FRANKLIN AND NOTTOWAY AT SEBRELL. SEE FLSAKQ FOR DETAILS. && .TIDES/COASTAL FLOODING... FORECAST UPDATED TO RAISE CSTL FLOOD WARNGS FOR THE ENTIRE BAY SIDE OF THE LWR ERN SHORE AS WELL AS THE WRN SHORE OF THE BAY NR THE NRN NECK AND MIDDLESEX COUNTY TDA WHERE MODERATE FLOODING IS EXPECTED. HI SURF ADVSRYS HAVE ALL EXPIRED. PREVIOUS DISCUSSION... A HIGH SURF ADVISORY REMAINS IN EFFECT ALONG THE ENTIRE ATLC COAST THRU 8 AM THIS MORNING...AS NEARSHORE WAVES REMAIN HIGH (8-11 FT). WATER LEVELS HAVE RISEN QUITE HIGH ACRS THE BAY AS ELEVATED SEAS ARE PREVENTING WATER FROM EXITING THE BAY AND TIDAL RIVERS. IN MOST AREAS THE SURGE HAS RISEN TO 2 FT OR GREATER. THUS...COASTAL FLOOD ADVISORIES HAVE BEEN ISSUED FOR ALL ZONES ADJACENT TO THE CHES BAY (BOTH THE WESTERN AND EASTERN SHORE) AS WELL AS THE TIDAL RIVERS THROUGH THE UPCOMING HIGH TIDE CYCLE (SEE CFWAKQ FOR DETAILS ON TIMES). THE COASTAL FLOOD ADVISORIES HAVE BEEN MAINTAINED FOR THE ATLC COAST AREAS THROUGH THE UPCOMING MORNING HIGH TIDE CYLE. && .AKQ WATCHES/WARNINGS/ADVISORIES...
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MD...COASTAL FLOOD WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ021>023. NC...NONE. VA...COASTAL FLOOD ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR VAZ084-086-089-090-093-095>097-523>525. COASTAL FLOOD ADVISORY UNTIL 2 AM EST WEDNESDAY FOR VAZ099-100. COASTAL FLOOD WARNING UNTIL 5 PM EST THIS AFTERNOON FOR VAZ075>078-085. MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST THURSDAY FOR ANZ634-650- 652-654-656-658. SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 5 AM EST THURSDAY FOR ANZ630>633.
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&& $$ SYNOPSIS...LKB NEAR TERM...LKB/SAM SHORT TERM...LKB/JAO LONG TERM...JDM AVIATION...MAS MARINE...TMG HYDROLOGY... TIDES/COASTAL FLOODING...

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