Area Forecast Discussion
Issued by NWS Wakefield, VA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KAKQ 191749 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1249 PM EST FRI DEC 19 2014 .SYNOPSIS... HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTHWEST TODAY INTO TONIGHT. WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. HIGH PRESSURE WILL BE OVER THE AREA AGAIN DURING SUNDAY. ANOTHER LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT. && .NEAR TERM /THROUGH TONIGHT/... LATEST SFC ANALYSIS DEPICTS ~993 MB LO PRES OVER THE CANADIAN MARITIMES WITH BROAD ~1027 MB HI PRES CENTERED OVER THE MIDWEST AND INTO THE MID ATLC/SE STATES. GENLY CLEAR SKIES OVER THE AKQ FORECAST AREA THIS MORNING...BUT BKN/OVC CONDITIONS PERSIST OVER NORTHERN VA AND SOME OF THIS HAS ROTATED SE AND WILL AFFECT THE NORTHERN NECK/ERN SHORE THROUGH EARLY AFTN. AS THE HIGH SPREADS E THIS AFTN SHOULD SEE THE CLOUDS ACRS THE NE ERODE. MAIN UPDATE WAS TO INCREASE CLOUD COVER OVER THE NE THROUGH 18Z (MOSTLY CLOUDY)...WHILE REMAINDER OF THE CWA WILL BE SUNNY TO MOSTLY SUNNY. MIXING AREA SOUNDINGS TO AROUND 925 MB SUPPORTS HIGHS RANGING FROM THE UPPER 40S/AROUND 50 F OVER INTERIOR NE NC AND SOUTH CENTRAL VA...TO THE LOWER TO MID 40S ON THE ERN SHORE. DRY WX CONTINUES TNGT WITH A MID-LEVEL S/W TROF APPROACHING THE AREA. THE MID ATLANTIC REMAINS INFLUENCED BY SFC HI PRES CENTERED OVER THE OH VALLEY. EXPECT LIGHT NW WINDS...A PARTLY CLOUDY SKY...AND LO TEMPS MAINLY IN THE UPR 20S TO LWR 30S (TEMPS EXPECTED TO FALL RAPIDLY AND THEN BECOME NEARLY STEADY LATE IN THE EVENING AS CLOUDS SLOWLY INCREASE). && .SHORT TERM /SATURDAY THROUGH SUNDAY/... WEEKEND FORECAST CONTINUES TO TREND DRIER. SFC LO PRES SLIDES E FM THE GOM SAT...WITH JUST A WEAK SFC REFLECTION OF THE LO SHOWING OFF THE SE CST SAT NGT. 00Z GUIDANCE KEEPS THE NRN ADVANCEMENT OF PCPN SAT NEAR THE NC/VA BORDER ON AVG. HAVE CAPPED POPS AT 20-30%...AND ONLY S OF I-64. COULD BE SOME SN/PL MIXED IN OVR THE SRN PIEDMONT BUT PRIMARILY EXPECTING RA. ANY PCPN ENDS EVERYWHERE BY LATE SAT AFTN. DRY CONDS THEN FOR SAT NGT AND SUN AS HI PRES CENTERED OVR THE NE STATES STRETCHES DOWN INTO THE MID ATLANTIC. TEMPS OVR THE WEEKEND WILL BE BLO NORMAL...WITH HIGHS MAINLY IN THE 40S. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... FORECAST UPDATED TO RAISE POPS THRU THE PERIOD (E.G. 60% MON AND TUE NGT/WED) AS CONFIDENCE FOR PCPN AS INCREASED. PREVIOUS DISCUSSION... LOW PRESSURE IS EXPECTED TO DEVELOP OFF OFF THE SOUTHEAST COAST AND TRACK NE OFF THE MID ATLANTIC COAST MONDAY INTO MONDAY NIGHT. TIMING DIFFERENCES CONTINUE AMONGST 18/12Z NUMERICAL GUIDANCE...AND GIVEN THIS POPS WILL REMAIN CAPPED IN THE CHC CATEGORY. POPS INCREASE TO 20-30% SUNDAY NIGHT...WITH 40-50% POPS ACROSS THE AREA MONDAY AND MONDAY NIGHT. PCPN TYPE SHOULD GENERALLY BE RAIN...ALTHOUGH THERE COULD BE A BRIEF PERIOD OF SLEET AT THE ONSET OVER THE NW PIEDMONT LATE SUNDAY NIGHT AND EARLY MONDAY MORNING. HIGHS MONDAY SHOULD RANGE FROM THE LOW 40S NW...TO MID 50S SE...AFTER MORNING LOWS IN THE LOW 30S NW...TO AROUND 40 SE. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY (BRINGING MILDER CONDITIONS WITH HIGHS IN THE LOW 50S NW TO NEAR 60 SE)...BEFORE LOW PRESSURE AND A STRONG COLD FRONT IMPACT THE REGION TUESDAY NIGHT INTO WEDNESDAY. SPATIAL AND TIMING DIFFERENCES CONTINUE WITH THE 18/12Z GFS TRACKING THE SURFACE LOW W OF THE MOUNTAINS...AND THE 18/12Z ECMWF TRACKING THE SURFACE LOW UP THE COASTAL PLAIN. THIS WILL HAVE IMPACT ON TEMPERATURES AND WHETHER THE RAIN IS MORE STRATIFORM OR SHOWERY. IF THE FARTHER W 18/12Z GFS WERE TO VERIFY THERE COULD BE A POTENTIAL FOR THUNDER. HOWEVER...EVEN WITH THIS SOLUTION...SURFACE DEWPOINTS AOA 60F REMAIN OFFSHORE. DRY AND BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... THERE IS A VERY DISTINCT BOUNDARY BTWN BKN-OVC STRATOCUMULUS (AROUND 3500 FT AGL) OVER NRN VA AND THE MD/VA LOWER EASTERN SHORE VERSUS THE REST OF THE REGION...WHERE AN AREA OF SUBSIDENCE PASSING FROM WEST TO EAST IS KEEPING SKIES CLEAR. IN ADDITION...NW WINDS ARE GUSTING TO 15-20 KT WITHIN AND JUST SOUTH OF THE STRATUS DECK. THE GUSTY WINDS WILL CALM DOWN BY SUNSET BUT THE STRATUS WILL REMAIN STEADFAST THROUGH TONIGHT INTO SATURDAY MORNING. WINDS AT KORF TURN MORE TO THE NORTH OVERNIGHT AND A STRATUS DECK AROUND 2000 FT AGL COULD DEVELOP OFF THE BAY. OTHERWISE...HIGH CLOUDS WILL INCREASE ACROSS THE REGION FROM THE SW AFTER 20/0700Z TONIGHT. LOW PRESSURE TRACKS WELL SOUTH OF THE AREA SAT/SAT NIGHT WITH CLOUDS THICKENING AND LOWERING AS SATURDAY PROGRESSES. STEADY PRECIPITATION WILL BE SHUNTED WELL SOUTH OF THE AREA...HOWEVER THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS ALONG AND SOUTH OF THE VA/NC BORDER FROM LATE MORNING THROUGH THE AFTN. PRECIP COMES TO AN END SATURDAY EVENING AND CONDITIONS WILL GRADUALLY IMPROVE FROM WEST TO EAST THROUGH THE REST OF SAT NIGHT. HIGH PRESSURE BUILDS TO THE NORTH OF THE AREA SUNDAY. A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS AND VISIBILITIES BEGINNING MONDAY. && .MARINE... SURGE BEHIND DEPARTING S/W SHUD REMAIN BLO SCA LVLS THIS MORNING ALTHOUGH A GUST OR TWO TO 20 KTS ACROSS THE BAY NOT OUT OF THE QSTN THRU NOON. HIGH PRESSURE THEN BUILDS INTO THE AREA THROUGH SATURDAY KEEPING A NRLY FLOW GOING AOB 15 KTS. LOW PRESSURE DEVELOPS OFF THE SE COAST SUNDAY NIGHT...THEN TRACKS NE OFF THE MID ATLANTIC COAST MON & MON NIGHT. THERE IS LITTLE TO NO CAA IN THE WAKE OF THIS LOW...SO CONDITIONS SHOULD REMAIN SUB-SCA WITH A WIND BECOMING WESTERLY BY TUE. A STRONGER LOW TRACKS W OF THE MOUNTAINS TUES NIGHT...WITH A STRONG COLD FRONT CROSSING THE MID ATLANTIC COAST WED MORNING. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAS/TMG NEAR TERM...LKB/MAS SHORT TERM...MAS LONG TERM...AJZ/MAS AVIATION...BMD/MPR MARINE...MPR

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.