Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 181554 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 1054 AM EST TUE NOV 18 2014 .SYNOPSIS... A COLD FRONT MOVES FARTHER OFFSHORE THIS MORNING AS SHARPLY COLDER AND DRIER CONDITIONS RETURN IN ITS WAKE. HIGH PRESSURE WILL BUILD ACROSS THE SOUTHEAST TONIGHT THROUGH MIDWEEK...BRINGING A MODEST WARM UP THROUGH MIDWEEK. A WEAK...DRY FRONTAL SYSTEM WILL CROSS THE REGION THURSDAY...WITH HIGH PRESSURE REBUILDING OVER THE AREA LATER THURSDAY AND FRIDAY. && .NEAR TERM /THROUGH TONIGHT/...
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LATEST WATER VAPOR IMAGERY AND MORNING RAOB UPPER AIR PLOTS DEPICT BROAD UPPER LEVEL TROUGH ENCOMPASSING MUCH OF THE CONUS THIS MORNING. AT THE SFC...STRONG 1035MB HIGH (+2 STD DEV MLSP) IS LOCATED OVER THE SRN PLAINS/LOWER MS VALLEY AS LAST EVENINGS STRONG COLD FRONT LOCATES OFFSHORE. MORNING TEMPS HAVE BOTTOMED OUT IN THE LOW TO MID 30S INLAND TO UPPER 30S TO NEAR 40 NEAR THE COAST. IN FACT...MUCH OF THE CONUS WOKE UP THIS MORNING WITH FREEZING TEMPS...MINUS COASTAL AREAS/FL/CA AND THE DESERT SW. FOR TODAY...H85 TEMPS ANALYZED AT -7C ON THIS MORNINGS KWAL SOUNDING WILL CONTINUE TO FALL THRU THE DAY AS CAA PERSISTS...DROPPING BETWEEN -10 AND -12C BY THIS EVENING (-2 TO -3 STD DEV). STRONG 180+ KT UPPER JET EXITS THE MID-ATLANTIC COAST THIS EVENING AS THE ANOMALOUS UPPER LOW BEGINS TO FILL AND EJECT NEWD TOWARDS LABRADOR LATE TODAY AND TONIGHT. MEANWHILE...SFC HIGH PRESSURE BUILDS EWD INTO THE GULF STATES/DEEP SOUTH. PRESSURE GRADIENT BETWEEN THIS FEATURE AND QUICKLY DEEPENING SFC LOW PRESSURE TO THE NORTH...IN TANDEM WITH AFOREMENTIONED STRONG CAA WILL BRING A BLUSTERY/COLD/RAW DAY TO THE LOCAL AREA. NW WINDS OF 15 TO 20 MPH THIS MORNING AND EARLY AFTERNOON, WITH GUSTS UP TO 20-25 MPH INLAND, 30-35 MPH NEAR THE COAST WILL PRODUCE WIND CHILLS IN THE UPPER 20S TO LOW 30S THROUGH MUCH OF THE DAY. PLUMMETING LLVL THICKNESSES TO BELOW 1300 DM (1000-850MB) AND STRONG CAA WILL LIMIT THE DIURNAL CURVE TODAY, WITH TEMPS GOING UP ONLY A FEW DEGREES FROM THE SUNRISE TEMP. AFTERNOON TEMPS GENERALLY ONLY IN THE MID TO UPPER 30S TO AROUND 40 ALONG THE SE VA/NE NC COAST. CLIMATE RECORDS ARE ONCE AGAIN MENTIONED BELOW FOR REFERENCE...BUT HIGH TEMPS HAVE ALREADY OCCURRED TODAY...JUST AFTER MIDNIGHT. SKY WILL BE MOSTLY CLEAR FOR MOST, THOUGH DO EXPECT SOME SCANT MID TO HIGH CLOUDS AS SECONDARY PV LOBE PINWHEELS AROUND THE UPPER TROUGH THIS AFTN. THE COLDEST NIGHT OF THE SEASON EXPECTED TONIGHT AS THE SFC HIGH BUILDS TO THE WEST/SOUTHWEST. EXISTING RECORD LOW VALUES WILL BE CHALLENGED AT EACH OF OUR CLIMATE SITES (AGAIN, SEE BELOW). WIDESPREAD LOWS INTO THE TEENS INLAND...TO LOWER 20S JUST EAST OF I-95 AND MID TO UPR 20S ALONG THE IMMEDIATE ATLANTIC COAST. OUTER BANKS CURRITUCK...THE LONE HOLD OUT FOR THE LOCAL FALL FROST/FREEZE PROGRAM SHOULD BE ABLE TO BE CLEARED TONIGHT...AND A FREEZE WARNING HAS BEEN ISSUED FOR OVERNIGHT TONIGHT.
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&& .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... THE NEXT IN A SERIES OF FAST MOVING UPPER SHORTWAVES WILL DROP OUT OF THE CANADIAN PRAIRIES ACROSS THE NORTHERN PLAINS WEDNESDAY, WHICH WILL SHUNT A CLIPPER FRONT ACROSS THE MID MISS VLY TOWARDS THE GREAT LAKES WED-WED NIGHT. MEANWHILE, SFC HIGH PRESSURE WILL BECOME CENTERED ALONG THE SE COAST WITH RESULTANT S-SW WINDS BRINGING A SLIGHT MODERATION TO TEMPS ON WED, W/HIGHS EXPECTED IN THE UPPER 30S TO LOW 40S. MID LEVEL CLOUDS INCREASE OVER THE NW AHEAD OF THE APPROACHING FRONT WED NIGHT/EARLY THURS MORNING. NOT QUITE AS COLD WED NIGHT, WITH EARLY MORNING LOWS THU MORNING IN THE MID- UPPER 20S INLAND TO AROUND 30 ALONG THE IMMEDIATE COAST. && .LONG TERM /THURSDAY THROUGH MONDAY/... SFC LOW PRESSURE MOVES ACROSS THE GREAT LAKES THU MORNING, WITH THE ASSOCIATED DRY COLD FRONT CROSSING THE LOCAL AREA THROUGH THE DAY ON THU, AND SLIDING OFF THE COAST THURSDAY NIGHT AS HIGH PRESSURE BUILDS IN ON ITS HEELS FROM THE OHIO VALLEY. SFC HIGH BECOMES CENTERED ACROSS THE ERN STATES INTO THE WEEKEND. MODELS DRY WITH TMPS REMAINING BLO NORMAL THROUGH SAT. HIGHS EACH DAY IN THE M40S- L50S. LOWS M20S- L30S. HIGHS MOVES OFFSHORE SATURDAY NIGHT AHEAD OF APPRCHG SYSTEM FROM THE SOUTHERN PLAINS/LWR MS VLY. LOW LEVEL SSW (RETURN) FLOW BEGINS TO OVERSPREAD THE AREA SAT NGT AND SUNDAY. RATHER LARGE DISCREPANCY WITH RESPECT TO MAXIMA ON SUNDAY WITH 00Z DATA. WARM FRONT STREAMS NORTH ACROSS THE COASTAL PLAIN AND EASTERN PORTIONS OF THE AREA SUNDAY. MEANWHILE, A WEAK WEDGE LOOKS TO SETUP ACROSS THE PIEDMONT, POTENTIALLY AIDED BY OVERRUNNING MOISTURE STREAMING NORTH FROM THE TN VLY. POPS GRADUALLY INCREASE SUNDAY AS NEG TILTED SOUTHERN STREAM SHORTWAVE PHASES WITH NORTHERN STREAM UPPER TROUGH DIVING ACROSS THE PLAINS SUNDAY. IN SHORT, MADE SOME MINOR ADJUSTMENTS TOWARD THE COOLER ENVELOPE OF GUIDANCE ON SUNDAY (ESP INLAND). HIGHS L50S INLAND TO L60S AT THE COAST. SLY FLOW AHEAD OF FRONT KEEPS SUN NIGHT WET AND MILD. LOWS U40S-U50S. ANTHR COMPLEX SYSTEM EARLY NEXT WEEK AS TEMPS / PCPN WILL ALL DEPEND ON FRNTL LCTN AS WRM FRNT LIFTS FARTHER NORTH AND COLD FRNT APPRCHS FROM THE WEST. COULD SEE ANTHR REPEAT OF TODAY WITH TMPS ALONG THE COAST JUMPING INTO THE 70S BUT REMAINING IN THE 50S ACROSS THE PIEDMONT. KEPT PCPN SHWRS ATTM. CONFIDENCE NOT HIGH ENUF TO FCST TSTMS ATTM. && .AVIATION /16Z TUESDAY THROUGH SATURDAY/... STRATUS BTWN 3500-4500 FT AGL IS MOVING OFF THE MID ATLANTIC COAST THIS MORNING WITH PRIMARILY MOSTLY CLEAR SKIES EXPECTED THE REST OF TODAY. THE COLDER MODIFIED ARCTIC AIRMASS HAS FINALLY ARRIVED TO THE REGION AND W-NW WINDS HAVE ALREADY BECOME BREEZY AS A RESULT. BREEZY WINDS WILL CONTINUE THROUGH TODAY AS THE COLDER AIR...A TIGHT SFC PRESSURE GRADIENT...AND A STRONG JET STREAK ENHANCE MIXING OF STRONGER WINDS ALOFT TO THE SFC. GUSTS SHOULD BE AROUND 20KT ACROSS THE REGION...WITH HIGHER GUSTS OF 25-30KT OVER THE MD/VA LOWER EASTERN SHORE AND AT CHES BAY/ATLANTIC OCEAN BEACHES. HIGH PRESSURE BUILDS INTO THE SE STATES TONIGHT...EXTENDING UP INTO THE MID ATLANTIC REGION THROUGH WED. AS THIS OCCURS...THE SFC PRESSURE GRADIENT WILL START TO RELAX THIS EVENING AND WEST WINDS WILL BEGIN TO DIMINISH. WINDS ARE NOT EXPECTED TO FULLY DECOUPLE UNTIL WED EVENING. A DRY COLD FRONT PASSES ACROSS THE REGION ON THU...BRINGING ANOTHER ROUND OF BREEZY SW-W WINDS TO THE AREA DURING THE AFTN. HIGH PRESSURE THEN SETTLES OVER THE MID ATLANTIC REGION FRI AND SAT. && .MARINE... THE ARRIVAL OF COLDER AIR OVER THE WATERS HAS BEEN DELAYED DUE TO THE PRESENCE OF LOW STRATUS OVERHEAD EARLY THIS MORNING. WHERE CLEARING HAS OCCURRED (MAINLY FAR NRN CHES BAY/POTOMAC RIVER)...A NOTICEABLE INCREASE IN WIND SPEEDS CAN BE OBSERVED. GALE FORCE GUSTS HAVE YET TO BE OBSERVED...HOWEVER THE COMBINATION OF A DECENT CAA SURGE/TIGHT SFC PRESSURE GRADIENT/STRONG JET STREAK WILL ALL WORK IN TANDEM TO ENHANCE MIXING OF STRONGER WINDS ALOFT TO THE SFC THROUGH THE REST OF THIS MORNING INTO EARLY THIS AFTN. HAVE MAINTAINED CURRENT GALE/SCA HEADLINES THROUGH TONIGHT. AS MENTIONED IN PREVIOUS DISCUSSIONS...GALES WILL LIKELY BE REPLACED WITH SCA FLAGS THIS AFTN AS WINDS MIX OUT TO MORE UNIFORM SPEEDS ACROSS ALL WATERS. WEST WINDS REMAIN BREEZY OVERNIGHT AND SCA HEADLINES WILL CONTINUE DURING THIS TIME. WINDS BEGIN TO DIMINISH AROUND SUNRISE WED MORNING AS HIGH PRESSURE BUILDS INTO THE SE STATES TONIGHT/WED AND THE PRESSURE GRADIENT RELAXES OVER THE WATERS. HAVE MAINTAINED SCA END TIME OF 7 AM WED MORNING SINCE WINDS AND WAVES/SEAS WILL ALL BE AT SUB-SCA LEVELS. A DRY COLD FRONT APPROACHES THE WATERS WED NIGHT AND IS EXPECTED TO CROSS THE WATERS ON THU. MODELS ARE TRYING TO DEPICT LOW-END SCA WINDS WED NIGHT INTO THU...WHILE MODEL TEMPS WOULD SUPPORT SCA CONDITIONS BEHIND THE FRONTAL PASSAGE AND ANOTHER REINFORCING SHOT OF COLD AIR/TIGHT PRESSURE GRADIENT. SINCE COLD AIR OVER WARMER WATERS IS A PREFERRED SET-UP FOR DECENT MIXING/SCA CONDITIONS...WILL KEEP THE FORECAST AS IS RATHER THAN REDUCE WIND SPEEDS WED NIGHT. HIGH PRESSURE SETTLES OVER THE MID ATLANTIC REGION FRI AND SAT. && .CLIMATE... ANOTHER ROUND OF UNSEASONABLY COLD WX IS EXPECTED TUESDAY THROUGH WEDNESDAY. TUE...RECORD LOW MAXIMUM TEMPERATURE RIC 34/1959 ORF 36/1924 SBY 33/1959 ECG 38/1959 TUE NGT...RECORD LOW MINIMUM TEMPERATURE RIC 18/1936 ORF 25/1959 SBY 17/1936 ECG 21/1959 WED...RECORD LOW MAXIMUM TEMPERATURE RIC 37/1951 ORF 38/1951 SBY 35/1951 ECG 39/1951 && .AKQ WATCHES/WARNINGS/ADVISORIES...
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MD...NONE. NC...FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EST WEDNESDAY FOR NCZ102. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST WEDNESDAY FOR ANZ630>638- 650-652-654-656-658.
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&& $$ SYNOPSIS...MAM NEAR TERM...MAM/SAM SHORT TERM...MAM LONG TERM...MPR AVIATION...BMD MARINE...BMD CLIMATE...

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