Area Forecast Discussion
Issued by NWS Wakefield, VA

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000 FXUS61 KAKQ 202345 AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 645 PM EST THU NOV 20 2014 .SYNOPSIS... DRY COLD FRONT PUSHES OFFSHORE THIS EVENING AS HIGH PRESSURE BUILDS OVER THE OHIO VALLEY. HIGH PRESSURE CENTERS OVER THE REGION FRIDAY AND FRIDAY NIGHT....PUSHING OFFSHORE LATE SATURDAY. A WARM FRONT LIFTS OVER THE REGION SUNDAY BEFORE A TRAILING COLD FRONT CROSSES THE REGION EARLY NEXT WEEK. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... TEMPS HAVE WARMED INTO THE MID-UPPER 50S THIS AFTERNOON THANKS TO GUSTY SW WINDS OF 20-30 MPH AND MODEST WAA. HOWEVER...THE CLIPPER FRONT IS STILL YET TO PUSH THRU THE REGION...WHICH WILL BRING A REINFORCING SHOT OF COLD AIR INTO THE REGION TONIGHT. THE FRONT WILL PUSH THRU THE REGION AND OFFSHORE THIS EVENING AS A POTENT UPPER SHORTWAVE TRACKS INTO NEW ENGLAND. A FEW MID LEVEL CLOUDS MAY ACCOMPANY THE FRONT...BUT SKIES REMAIN GENERALLY MOSTLY CLEAR. TEMPS WILL FALL OFF BEHIND THE FRONT AS CAA ENSUES. LOW-LEVEL THICKNESSES DROP OFF 50-60 METERS THIS EVENING THRU EARLY FRI MORNING...RESULTING IN TEMPS FALLING INTO THE MID-UPPER 20S INLAND TO LOW-MID 30S NEAR THE COAST. NW WINDS GENERALLY 5-10 MPH INLAND...WITH GUSTS UP TO 25 MPH ALONG THE IMMEDIATE COAST. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/... PERSISTENT CYCLONIC FLOW OVER THE ERN CONUS FINALLY EJECTS EWD OFF THE NE COAST AS A STRONG 150+ KT UPPER JET EXITS THE MID- ATLANTIC COAST. STRONG ~1035MB SFC HIGH PRESSURE BUILDS OVER THE OH VALLEY EARLY FRI BEFORE CENTERING OVER THE LOCAL AREA LATE FRI- FRI NIGHT. CAA WANES FRI AFTERNOON...BUT H85 TEMPS WILL HAVE REACHED -8 TO -10C (-1 TO -2 STD DEV). THE RESULT WILL BE WELL BELOW NORMAL DAYTIME TEMPS...GENERALLY IN THE MID 30S IN THE NW TO MID 40S SE (-2 STD DEV OR NEARLY 20 DEGS BELOW NORMAL). SOME RECORD LO MAX READINGS MAY BE IN DANGER. NW WINDS WILL GUST UP TO 20-25 MPH DURING THE AFTERNOON BEFORE THE PRESSURE GRADIENT RELAXES LATE. SFC HIGH CENTERS OVER THE REGION FRI NIGHT. CALM- LIGHT WINDS AND CLEAR SKIES WILL ALLOW TEMPS TO DROP BACK INTO THE MID-UPPER TEENS TO LOWER 20S INLAND. UPPER 20S- LOW 30S NEAR THE COAST. RETURN FLOW ON THE BACK SIDE OF DEPARTING UPPER/SFC HIGH PRESSURE SAT AFTERNOON WILL RESULT IN MODERATING TEMPS AND INCREASING THICKNESSES. H85 TEMPS ALSO RECOVER QUICKLY FRI NIGHT- SAT...WARMING TO AROUND +6C BY LATE SAT. HIGHS WILL BE SLOW TO RECOVER...WARMING ONLY INTO THE UPPER 40S NW TO LOW 50S SE (STILL 10 DEGS BELOW NORMAL). MEANWHILE...SRN STREAM SHORTWAVE AND ASSOCIATED SFC LOW MOVE INTO THE SRN PLAINS SAT AS ZONAL FLOW DEVELOPS OVER THE LOCAL AREA. H85 HIGH PUSHES OFFSHORE LATE SAT WITH FLOW ON THE WRN PERIPHERY TAPPING INTO GULF MOISTURE. MID- UPPER CLOUDS WILL INCREASE LATE SUN INTO SUN NIGHT FROM THE WEST AS MOISTURE ADVECTION STRENGTHENS. WARM FRONT LIFTS INTO THE TN/KY VALLEYS LATE SAT NIGHT...EXTENDING INTO THE SE STATES. SHORTWAVE EJECTS NEWD FROM THE SRN PLAINS LATE SAT NIGHT INTO SUN MORNING...LIFTING OVER THE CNTRL APPALACHIANS SUN. MODELS COMING INTO BETTER AGREEMENT WITH TIMING OF THE PRECIP...BUT AS IS TYPICAL WITH OVERRUNNING EVENTS AND THE PRESENCE OF AN UPSTREAM 120+ KT UPPER JET...WILL KEEP POPS EARLY SUN ACROSS THE PIEDMONT INTO CNTRL VA. MAIN BRUNT OF DYNAMICS/MOISTURE/PRECIP QUICKLY SPREADS ACROSS THE REGION SUN AFTERNOON-EVENING. DIFFLUENCE/DIVERGENCE ALOFT AND THE LIFTING SHORTWAVE WILL PROVIDE DYNAMIC FORCING FOR ASCENT OVER THE REGION. OVERRUNNING COMMENCES AS THE WARM FRONT LIFTS INTO THE REGION SUN AFTERNOON. PER GEFS STD ANOMALIES...H85 MOISTURE FLUX IS PROGGED AT +3 TO +4 STD DEV WITH PWATS INCREASING TO AROUND 1.4 INCHES. SOUNDINGS ALSO DEPICT A DEEPLY SATURATED COLUMN. AS A RESULT...LOCALLY HEAVY RAINFALL IS POSSIBLE. HAVE RETAINED CATEGORICAL POPS SUN AFTERNOON AND SUN EVENING AS THE WARM FRONT LIFTS THRU THE REGION. BRUNT OF PRECIP WILL LIKELY PUSH OFFSHORE SUN NIGHT AS A DRY SLOT PUNCHES INTO THE REGION. TEMPS SUN WILL WARM INTO THE UPPER 50S NW TO MID 60S SE. LITTLE DIURNAL TREND EXPECTED SUN NIGHT AS TEMPS ONLY FALL A FEW DEGS INTO THE LOW 50S NW TO UPPER 50S SE. && .LONG TERM /MONDAY THROUGH THURSDAY/... MODELS DIFFER WRT TIMING OF THE CDFRNTL PASSAGE ACROSS THE AREA. GFS ABT 6 HRS FASTER THAN EURO MON NIGHT. EITHER WAY...MONDAY APPEARS TO BE A WARM AND BREEZY DAY AS FA BECOMES WARM SECTORED WELL AHEAD OF CDFRNT. KEPT LOW CHC POP GOING FOR ANY SHWR THAT DVLPS IN THE WRMR AIRMASS. HIGHS U60S-M70S. CHC POPS MON NIGHT WITH FROPA. LOWS M-U40S...XCPT 50-55 SERN CSTL AREAS. KEPT LOW CHC POPS ACROSS ERN AREAS TUE AS A WEAK S/W MOVES NE ALONG THE FRNT AS IT SLOWLY MOVES OFF THE COAST. OTW...DRIER AND COOLER AIR MOVES IN FROM THE WEST. HIGHS U50S-L60S. LOWS TUE NITE M30S-M40S. HIGHS PRES FROM THE WEST (PACIFIC ORIGIN VS CANADIAN) ALLOWS FOR A QUIET MID WEEK PRD. DRY WX THRU TURKEY DAY ALONG WITH A GRDL COOLING TREND. HIGHS WED 50-55. LOWS WED NITE U20S-U30S. HIGHS THURSDAY U40S-L50S. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... AS OF 23Z...A POORLY DEFINED COLD FRONT OVER THE MID ATLANTIC STATES WILL EVENTUALLY MAKE IT OFF THE COAST OVERNIGHT. HAVE WINDS SHIFTING TO NW AT THE TAF SITES BETWEEN 03 AND 07Z. THE SKY WILL REMAIN CLEAR DURING THE NEXT 24 HOURS. NW WINDS BECOME GUSTY (15-20 KTS) FRIDAY AFTERNOON. OUTLOOK...HIGH PRESSURE SETTLES OVER THE MID-ATLANTIC REGION FRI AND SAT...MOVING WELL OFFSHORE LATE SATURDAY. A COMPLEX WEATHER SYSTEM IS EXPECTED TO BRING PERIODS OF RAIN SUNDAY THROUGH MONDAY WITH IFR CONDITIONS POSSIBLE. && .MARINE... THE GUSTY SW WINDS AHEAD OF THE FRNT WILL DMNSH A BIT THIS EVENING BEFORE BCMG W-NW AFTR MIDNITE AS STRNG CAA SETS IN POST FROPA. LATEST DATA SUGGESTS THE SURGE (15-20 KTS) LASTS TILL ARND 18Z FRI ACROSS THE BAY AND SND SO HAVE XNNDD THE SCA HEADLINES ACROSS THOSE AREAS SVRL MORE HRS. CSTL WTRS A BIT DIFFERENT AS WNDS ARND 25 KTS SHUD DMNSH AFTR 12Z. SEAS HAVING TROUBLE REACHING 5 FT ACROSS SRN CSTL WTRS AND MAY ONLY REACH THOSE VALUES OUT NR 20 NM. THUS...WILL LET THE SCA ON CSTL WTRS EXPIRE LATE TONITE/ERLY FRI THERE. HIGH PRESSURE SETTLES OVER THE MID ATLANTIC REGION FRI NIGHT THRU SAT NIGHT THEN MOVES WELL OFFSHORE SUNDAY RESULTING IN WINDS AND SEAS BLO SCA LVLS. NEXT CHC FOR SCA`S WILL COME LATE SUN INTO MON AS SRLY WINDS INCRS AHEAD OF NEXT SYSTEM APPROACHING FROM THE SW. TONIGHTS TIDES PROGGED ABOUT A HALF TO THREE QUARTERS OF A FOOT BELOW NORMAL. TIDES EXPECTED TO SLOWLY RETURN TO NEAR NORMAL OVER THE NEXT FEW DAYS. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...NONE. NC...NONE. VA...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR ANZ630>634. SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR ANZ638-652-654- 656-658. SMALL CRAFT ADVISORY UNTIL 10 AM EST FRIDAY FOR ANZ650. && $$ SYNOPSIS...SAM NEAR TERM...SAM SHORT TERM...SAM LONG TERM...MPR AVIATION...LSA MARINE...MPR

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