Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 191927 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 327 PM EDT FRI SEP 19 2014 .SYNOPSIS... A TROF OF LOW PRESSURE DRIFTS WEST AND OVER THE MOUNTAINS TODAY. HIGH PRESSURE BUILDS SOUTH AND ACROSS THE MID ATLANTIC REGION THROUGH SUNDAY. A COLD FRONT CROSSES THE AREA SUNDAY NIGHT. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... LATEST MSAS INDCTG WEAK SFC TROF FROM SRN DELAWARE SW ACROSS THE VA & NC PIEDMONTS. LATEST RADAR TRENDS SHOW SCT SHWRS ALONG THIS BNDRY MAINLY ALONG RT 460 WEST OF PTB. MODELS AGREE IN SHIFTING THIS TROF WEST ACROSS THE MTS TODAY WITH HIGH PRESSURE BUILDING INTO THE AREA FROM THE NORTH. TSCTNS SHOWING ENUF MSTR AT DIFFERENT LEVELS FOR SCT-BKN CLOUDS ALONG WITH A NE WIND FLOW. ANY TRIGGER FOR SCT SHWRS DRIFTS WEST THRU OUT THE DAY. GIVEN THESE TRENDS...HELD ONTO CHC POPS THIS MORN ACROSS THE WRN HALF OF FA ALTHOUGH CHCS DECREASE TO SLGHT CHC BY LATE AFTRN. OTW... VRBL CLDNS WITH HIGHS IN THE M-U70S. && .SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/... VRBL CLDNS AGAIN TONIGHT BUT DRY AS SPRT FOR ANY SHWRS SHIFTS WEST. SOME PTCHY FOG PSBL BUT WON`T INCLUDE IN GRIDS ATTM. LOWS IN THE M50S-L60S. NE FLOW CONTINUES ON SAT AS THE SFC HIGH MOVES FARTHER OFF THE NEW ENGLAND COAST. TSCTNS SHOWING SOME DRYING AT MID LEVELS FOR MOST OF THE DAY SO WILL KEEP A DRY FCST UNDER PT TO MSTLY SUNNY SKIES. H85 TMPS RISE TO BTWN 12-14C ALLOWING HIGHS TO TOP OUT IN THE U70S-M80S. SFC LOW PRESSURE PROGGED TO DVLP OFF THE SERN COAST SAT THEN TRACK NE ALONG THE GULF STREAM SAT NIGHT AND SUN MORNING BEFORE LIFTING NE AND AWAY FROM THE AREA SUN AFTRN. STILL SOME MODEL DIFFERENCES WRT HOW FAR WEST MSTR FROM THIS SYSTM GETS. FOR NOW...WILL CONTINUE TO HIGHLIGHT MORE CLOUDS OVR ERN HALF OF FA WITH SLGHT CHC POPS ALONG THE COAST SAT NIGHT AND SUN MORNING. LOWS SAT NIGHT U50S-M60S. LOW PRESSURE TRACKS NE AND AWAY FROM THE RGN SUN WHILE THE NXT COLD FRNT APPRCHS FROM THE WEST. DATA SUPPORTS SUBSIDENCE BEHIND THIS SYSTM RESULTING IN SKIES BCMG PT TO MSTLY SUNNY BY THE AFTRN. H85 TMPS APPRCH SUMMER LEVELS (14-16C) ALLOWING HIGHS TO REACH THE M-U80S. A 90 DEGREE READING IS PSBL OVR THE PIEDMONT GIVEN HOW DRY THE GROUND IS ATTM. ADJUSTED SUN NIGHTS FCST A BIT GIVEN THE LATEST TRENDS OF MSTR ALONG THE COLD FRONT. EXPECT SCT CONVECTION TO DVLP ACROSS THE MTS LATE SUN AFTRN THEN DRIFT SE ACROSS THE NRN HALF OF THE FA WHILE WEAKENING SUN EVENING. ADDED SLGHT CHC THUNDER GIVEN HOW WARM / MARGINAL INSTAB PROGGED OUT AHEAD OF BNDRY. KEPT SERN HALF OF FA DRY FOR NOW. LOWS IN THE 60S. && .LONG TERM /MONDAY THROUGH FRIDAY/... A REINFORCING COLD FRONT WILL USHER IN BELOW NORMAL TEMPS THROUGH THE EXTENDED AS COOL CANADIAN HIGH PRESSURE BUILDS OVER THE THE NE. MEDIUM RANGE GUIDANCE IN FAIRLY GOOD AGREEMENT OVER THE ERN CONUS WITH THE EVOLVING AMPLIFIED UPPER AIR PATTERN. AMPLIFIED PATTERN WILL FEATURE A LONGWAVE TROUGH OVER THE ERN CONUS TO BEGIN THE PERIOD. AN ASSOCIATED SECONDARY/REINFORCING COLD FRONT WILL SWEEP THROUGH THE REGION MONDAY MORNING. MOISTURE WILL BE RATHER LIMITED ALONG THE FRONT (PWATS ~1.5 INCHES)...BUT HEIGHT FALLS AND INCREASING WINDS ALOFT (JET STREAK ROUNDING THE BASE OF THE UPPER TROUGH) WILL PROVIDE FORCING FOR ASCENT OVER THE REGION. SHOULD BE ENOUGH FOR SLIGHT CHANCE/ISOLATED POPS...WITH THE BEST COVERAGE OVER THE NRN LOCAL AREA. THE BIGGER HEADLINE WITH THE FRONT WILL BE THE DRY AIR AND COLD AIR ADVECTION POST FRONTAL AS HIGH PRESSURE BUILDS IN FROM THE W-NW. MON WILL BE A TRANSITION DAY AS THE COOLEST/DRIEST AIR LAGS BEHIND THE FRONT. REINFORCING SHORTWAVE CROSSES THE GREAT LAKES-NE STATES TUES AS THE TROUGH AXIS PUSHES OFF THE ERN SEABOARD. MEANWHILE...MID-LEVEL RIDGE WILL PROGRESS EWD OVER THE CNTRL PLAINS AND INTO THE ERN CONUS TUES- WEDS. COOL CANADIAN HIGH PRESSURE PROGGED TO BUILD OVER NEW ENGLAND WEDS. UPPER/SFC HIGH PRESSURE REMAINS OVER THE REGION THURS. THE RESULT WILL BE CONTINUED DRY CONDITIONS AND BELOW NORMAL TEMPS. HIGHS WILL BE BELOW AVG THRU THE PERIOD...WITH TUES AND WEDS BEING THE COLDEST DAYS AT NEARLY -1 STD DEV (LOW-MID 70S). WENT A LITTLE ABOVE WPC GUIDANCE AS LOW LEVEL THICKNESSES YIELD SLIGHTLY WARMER TEMPS UNDER MOSTLY SUNNY SKIES. LOWS GENERALLY IN THE LOW-MID 50S INLAND TO LOW 60S NEAR THE COAST. FEW LOCALES IN THE PIEDMONT MAY DROP INTO THE UPPER 40S AT NIGHT. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... STRONG HIGH PRESSURE OVER NEW ENGLAND WITH NE-E WINDS OVER THE CWA. VFR CONDS GENERALLY PREVAIL OVER THE REGION BUT WITH MID AND LOW CLOUDS DUE TO PLENTY OF MOISTURE OFF THE ATLANTIC. WINDS ARE MOSTLY 10 KT OR LESS BUT SOME GUSTY CONDS PERSIST CLOSE TO THE COAST. A FEW VERY LIGHT SHOWERS OVER THE REGION DUE TO A WEAK SFC TROF OR UPSLOPE IN THE PIEDMONT. NO SIG WX EXPECTED THRU THE PERIOD. CLOUDS WILL GRADUALLY THIN OUT THIS AFTN/EVENING FROM RIC EAST...WHILE MORE CLOUDINESS AND PSBL MVFR CONDS EXPECTED WEST OF RIC. OUTLOOK...MAINLY VFR AND DRY WEATHER ARE EXPECTED TO CONTINUE INTO SUN. AN AREA OF LOW PRES MOVG UP THE EAST COAST MAY BRING INCREASING CLOUDS AND CHC OF RAIN FOR NE NC AND SE VA LATE SUN INTO MON. && .MARINE...
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NELY TO ELY FLOW THIS AFTERNOON IS RESULTING FROM HIGH PRESSURE OVER NEW ENGLAND. GRADIENT HAS TIGHTENED A LITTLE THIS AFTERNOON ALLOWING FOR GUSTS OF 12-19KT ESPECIALLY AT THE MOUTH OF THE BAY AND OVER THE COASTAL WATERS. SEAS HAVE BEEN SLOW TO BUILD TODAY WITH 3 TO 4 FT SEAS OFF DUCK NC AND OFF OCEAN CITY. SEAS OFF SOUTHEAST VA REMAIN AROUND 3 FT. SEAS SOUTH OF DUCK HAVE BEEN BUILDING TO 5 TO 6 FT AND SEAS ARE STILL EXPECTED TO BUILD TO MARGINAL SCA LATER TONIGHT INTO SAT MORNING. SCA HEADLINES GO INTO EFFECT FOR ALL THE COASTAL WATERS AT 1 AM. HIGH PRESSURE PUSHES OFF THE NEW ENGLAND COAST SAT AS LOW PRESSURE DEVELOPS ALONG A STALLED BOUNDARY OFF THE NC COAST. THE LOW WILL SLOWLY LIFT ALONG THE BOUNDARY SATURDAY AND SUNDAY PASSING WELL OFF THE VA COAST LATE SUNDAY. THIS WILL RESULT IN A NELY TO NLY FLOW OVER THE COASTAL WATERS AND BAY FOR MOST OF THE WEEKEND. SCA CONDITIONS FOR WIND SPEEDS ARE NOT ANTICIPATED ATTM BASED ON THE GRADIENT WIND FORECAST. HOWEVER...SEAS WILL LIKELY REMAIN ELEVATED (4-5 FT) THRU SAT...BEFORE SUBSIDING ON SUNDAY AHEAD OF A COLD FRONT WITH WINDS TURNING OFFSHORE. SCA HAVE BEEN EXTENDED INTO SAT NIGHT AND MAY NEED TO EXTENDED INTO SUNDAY FOR SEAS. SFC LOW LIFTS NE OFF THE COAST LATE SUNDAY WITH A COLD FRONT FORECAST TO CROSS THE REGION MONDAY MORNING. SEAS MAY BRIEFLY BUILD TO 5 FT AGAIN SUNDAY NIGHT INTO EARLY MONDAY. NW WINDS 10-15 KT ON MONDAY WILL GRADUALLY BECOME N-NE ON TUESDAY. HIGH PRESSURE WILL LOCK IN ACROSS NEW ENGLAND AND EXTEND INTO THE MID ATLANTIC FOR A GOOD PORTION OF NEXT WEEK. THIS WILL RESULT IN A PROLONGED PERIOD OF NELY FLOW ACROSS THE REGION.
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&& .HYDROLOGY... LATEST DROUGHT INFO SHOWING AN AREA OF ABNORMALLY DRY CNDTNS ACROSS PORTIONS OF VA. THIS INCLUDES AREAS N OF I 64 & RT 360 (INCLUDING THE RIC METRO AREA) IN AKQ FA. OTHER THAN SCT CONVECTION WITH THE FRNT SUN EVE...XTNDD MODELS DO NOT SHOW MUCH IN THE WAY OF RELIEF FOR THE NEXT WEEK. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MDZ025. NC...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR NCZ102. VA...MODERATE RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR VAZ098>100. MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EDT SATURDAY FOR ANZ650- 652-654-656. SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 PM EDT SATURDAY FOR ANZ658. && $$ SYNOPSIS...MPR NEAR TERM...MPR SHORT TERM...MPR LONG TERM...JAO AVIATION...JEF MARINE...JAO HYDROLOGY...

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