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Area Forecast Discussion
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000
FXUS61 KAKQ 230752
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
352 AM EDT WED APR 23 2014

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION EARLY THIS MORNING. COOL
CANADIAN HIGH PRESSURE BUILDS BACK OVER THE REGION TONIGHT AND
THURSDAY. A SERIES OF WEAK FRONTS WILL CROSS THE AREA FRIDAY INTO
THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...

LATEST WX ANALYSIS FEATURES SFC COLD FRONT SLOWLY DROPPING
SOUTHEAST ACROSS THE LOWER MID-ATLANTIC THIS MORNING. EXPECT QUICK
CLEARING BEHIND THE FRONT THROUGH SUNRISE AS WINDS VEER AROUND TO
THE NW, AND WILL BECOME GUSTY LATER TODAY.

MODIFYING CANADIAN HIGH PRESSURE BUILDS TO OUR NW TODAY. BUFKIT
SOUNDINGS SUGGEST WINDS IN THE 15 TO 20 MPH RANGE, WITH FREQUENT
GUSTS TO 35-40 MPH ON THE ERN SHORE AND 25-35 MPH ELSEWHERE. A
MAINLY SUNNY/CLEAR SKY EXPECTED, ALTHOUGH A FEW SCATTERED CU WILL
PERSIST ACROSS THE ERN SHORE DUE TO COLD POOL ALOFT ON THE BACK SIDE
OF THE SHORTWAVE TROUGH. PLENTY OF SUN, DRYING FUELS AND GUSTY
WINDS WILL ADD UP TO A POTENTIALLY CRITICAL FIRE WEATHER DAY,.
HAVE ISSUED A RED FLAG WARNING FOR NORTHERN HALF OF THE AREA,
MAINLY FROM RIC NORTH, WITH AN SPS FOR INCREASED FIRE DANGER
OUTLOOKED OVER SOUTHERN HALF OF THE AREA.

FOR TEMPS, LOCAL THICKNESS TOOLS INDICATE HIGHS ONLY IN THE LOWER
TO MIDDLE 60S OVER THE LOCAL AREA. HOWEVER, WITH DEWPOINTS MIXING
INTO THE UPR 20S/LOW 30S (YIELDING MINIMUM RH VALUES IN THE MID
20S INLAND) AND WITH DOWNSLOPE FLOW COMPONENT, EXPECT MAXIMA
MAINLY IN THE MID TO UPPER 60S INLAND ALL ZONES (NOT MUCH
DIFFERENCE AT THE COAST DUE TO STRONG NW FLOW). HIGH PRESSURE
BUILDS INTO THE REGION TONIGHT. EXPECT CHILLY EARLY MORNING LOWS
THU MORNING IN THE MID-UPPER 30S ALONG/W OF I-95 TO THE UPPER 30S
TO LOWER 40S ELSEWHERE UNDER A MAINLY CLEAR SKY. DO NOT EXPECT ANY 
FREEZE ISSUES AND PROBABLY TOO DRY FOR MUCH MORE THAN SOME PATCHY
FROST IN SHELTERED LOCALES. 

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...

DRY AGAIN ONCE AGAIN THU AS HIGH PRESSURE SLIDES OVER THE
NORTHEAST/MID-ATLANTIC REGION, BEFORE SLIDING OFF THE ATLANTIC
SEABOARD ERY FRIDAY. HIGHS THURS GENERALLY IN THE UPPER 60S (A
LITTLE COOLER NEAR THE COAST). ONCE AGAIN, MIN RH VALUES FALL INTO
THE 20S THU AFTN BUT WINDS WILL BE LIGHTER. NEXT FAST MOVING WAVE
OF MOISTURE MOVES IN FROM THE PLAINS ON FRI. GFS REMAINS FASTER
WITH BRINGING SYSTEM THROUGH, WITH THE NAM/ECMWF A BIT SHARPER
WITH THE UPPER WAVE...AND HENCE A BIT SLOWER. PUSHED BACK ONSET OF
POP JUST SLIGHTLY AND CONTINUED TO SPLIT THE DIFFERENCE BETWEEN
THESE STILL DIVERGENT SOLUTIONS. GIVEN THIS, EXPECT A SCENARIO
NOT UNLIKE THAT OF EARLIER YESTERDAY (TUESDAY); RATHER MEAGER
INSTABILITY WITH MODEST DEEP LAYER SHEAR/LAPSE RATES THAT RESULT
IN SOME WEAK DISORGANIZED CONVECTION LATE IN THE DAY FRIDAY. WILL
KEEP CHC POPS ALL ZONES FOR SCT SHRAS AND PERHAPS A THUNDERSTORM
PUSHING THROUGH AT SOME POINT IN THE AFTN/EVENING. WARMER SSW
FLOW SHOULD PUSH HIGHS WELL INTO THE 70S TO NEAR 8O.

CLEARING BEHIND THE FRONT FRIDAY NIGHT, WITH POPS QUICKLY ENDING
WEST TO EAST. LOWS GENERALLY IN THE 50S TO NEAR 60 ALONG AREA 
COASTLINES.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
PROGRESSIVE FLOW WILL BEGIN TO EVOLVE INTO A HIGHLY AMPLIFIED/BLOCKY 
PATTERN OVER THE CONUS DURING THE EXTENDED...LIKELY RESULTING IN A 
COOL/WET PERIOD BY EARLY NEXT WEEK. 

MEDIUM RANGE GUIDANCE TENDS TO STRUGGLE WITH BLOCKY FLOW...AND THIS 
IS NO EXCEPTION. TRENDED TOWARD ENSEMBLE AND WPC GUIDANCE TO SMOOTH 
OUT DIFFERENCES IN THE MODELS. OVERALL...UPPER PATTERN WILL BE 
CHARACTERIZED BY AN ANOMALOUS UPPER TROUGH OVER THE WRN CONUS...HIGH 
PRESSURE RIDGING FROM THE GULF STATES INTO THE NORTHWEST TERRITORIES 
AND ANOTHER UPPER TROUGH OVER SE CANADA AND NEW ENGLAND. WHILE 
MEANINGFUL DIFFERENCES EXIST IN THE MODELS...A SECOND (DRY) COLD 
FRONT IS PROGGED TO CROSS THE LOCAL AREA ON SAT. THIS FRONT WILL 
BRING COOLER/DRIER AIR TO THE REGION ON SUN. A STATIONARY BOUNDARY 
WILL THEN SET UP OVER THE MID-ATLANTIC REGION (DEPENDING ON THE 
MODEL IT COULD BE FROM THE CAROLINAS NWD TO THE MASON DIXON LINE). 
THIS BOUNDARY WILL BE THE FOCUS OF PRECIP EARLY NEXT WEEK. 
MEANWHILE...A BROAD AREA OF LOW PRESSURE OVER THE PLAINS WILL 
PROGRESS EWD SUN-TUES...TAPPING INTO GULF MOISTURE. WILL MAINTAIN 
SLIGHT CHANCE POPS SUN NIGHT-TUES BASED ON UNCERTAINTY...BUT 
INCREASE TO LOW-END CHANCE POPS TUES NIGHT AS THE UPPER/SFC LOW GETS 
CLOSER. 

HAVE TRENDED TO THE COOLER SIDE OF GUIDANCE WITH HIGHS GENERALLY IN 
THE MID-UPPER 60S SUN-TUES. OVERNIGHT LOWS GENERALLY IN THE UPPER 
40S-LOW 50S.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AS OF 23Z...PRE-FRONTAL SHOWERS HAVE PRACTICALLY DISSIPATED AND DID 
NOT INCLUDE ANY PCPN IN THE TAFS. A STRONG COLD FRONT WAS MOVING
THROUGH THE MOUNTAINS AND IS FORECAST TO REACH RIC/SBY SHORTLY
AFTER MIDNIGHT AND ECG AROUND 09Z/5AM EDT. BKN MID LEVEL CLOUDS
SHOULD QUICKLY CLEAR BEHIND THE FRONT. GUSTY NW OR N WINDS WILL
IMMEDIATELY FOLLOW THE FRONT. WINDS DIMINISH SOME (EXCEPT AT ORF)
A COUPLE OF HOURS FOLLOWING THE FRONTAL PASSAGE AND THEN INCREASE
ONCE AGAIN LATE WEDNESDAY MORNING. GUSTS MAY REACH OVER 30 KNOTS
AT SBY AND AROUND 25 KNOTS AT THE OTHER TAF SITES.

OUTLOOK...VFR CONDITIONS WILL CONTINUE THROUGH THURSDAY NIGHT. THE 
NEXT COLD FRONT CROSSES THE AREA FRIDAY WITH SCT SHWRS/TSTMS IN THE 
AFTERNOON. ANOTHER FRONT CROSSES THE AREA SATURDAY BUT THE WEEKEND 
IS FORECAST TO BE DRY.

&&

.MARINE...
PRE-FRONTAL TROUGH HAS ALIGNED ALONG THE WATERS LATE THIS
AFTERNOON AS A COLD FRONT LOCATES OVER THE CNTRL APPALACHIANS.
S-SW WINDS CURRENTLY OVER THE WATERS AVERAGING 10-15 KT WITH WAVES
1-2 FT AND SEAS 3-4 FT. COLD FRONT WILL CROSS THE WATERS THIS
EVENING AS A STRONG NW SURGE COMMENCES. PRESSURE GRADIENT
STRENGTHENS BTWN BUILDING CANADIAN HIGH PRESSURE OVER THE GREAT
LAKES AND THE DEPARTING COLD FRONT. 925MB WINDS INCREASE TO 35-40
KT AS LOW LEVEL LAPSE RATES SHARPEN. THE RESULT WILL BE SOLID SCA
CONDITIONS OVER THE WATERS...INCLUDING THE RIVERS AND SOUND.
DECIDED TO NOT GO LOW-END GALE BASED ON THE LIMITED STRENGTH OF
THE SFC PRESSURE GRADIENT AND COOL WATERS. HOWEVER...AN OCCASIONAL
GUST TO 35 KT IS POSSIBLE...ESPECIALLY OVER THE NRN BAY AND NRN
COASTAL WATERS. TOP OF THE MIXED LAYER AT KSBY YIELDS GUST TO ONLY
30-33 KT. WILL MONITOR FUTURE OBS/MODEL TRENDS TO SEE IF GALE
HEADLINES ARE NEEDED. REGARDLESS...CONDITIONS WILL DETERIORATE
RAPIDLY AROUND MIDNIGHT. WAVES WILL BUILD TO 3-5 FT IN THE
BAY...2-3 FT IN THE RIVERS AND 2 FT IN THE SOUND. SEAS WILL BUILD
TO 5-8 FT...HIGHEST IN THE NRN COASTAL WATERS. HIGH PRESSURE WILL
CONTINUE TO BUILD SWD OVER THE OH VALLEY WEDS AS SCA CONDITIONS
PERSIST THRU THE DAY. THE HIGH WILL NUDGE OVER THE WATERS WED
NIGHT...ALLOWING THE PRESSURE GRADIENT TO RELAX AND WINDS TO
DIMINISH. SCA HIGH PRESSURE WILL SLIDE OVER THE REGION
THURS...LOCATING OFFSHORE LATE THURS. FLOW WILL RETURN TO THE
SOUTH...WITH SEAS SUBSIDING BELOW 5 FT LATE THURS. SCA HEADLINES
FOR THE RIVERS AND SOUND DROP OFF LATE WEDS...LOWER JAMES AND BAY
THURS MORNING.

A WEAKER COLD FRONT CROSSES THE WATERS FRI AFTERNOON WITH A
SECOND COLDER FRONT CROSSING THE WATERS SATURDAY. SCA CONDITIONS
MAY BE POSSIBLE SAT NIGHT.

&&

.FIRE WEATHER...
GIVEN THE EXPECTED DRY AND BREEZY CONDITIONS LATER TODAY...AND
IN COORDINATION WITH STATE FIRE OFFICIALS/NEIGHBORING FORECAST
OFFICES, A RED FLAG WARNING HAS BEEN ISSUED FOR THIS AFTERNOON/EVENING
FOR PORTIONS OF CENTRAL AND EASTERN VA (MAINLY ALONG AND NORTH OF
RIC METRO AREA, AS WELL AS THE LOWER MD EASTER SHORE. WINDS ARE
EXPECTED TO BE THE STRONGEST THIS AFTN (20-25 MPH WITH GUSTS TO
35-40 MPH) ALONG AND NORTH OF A LINE FROM FVX-PTB-LFI...AND THIS
IS ESSENTIALLY THE WARNING AREA. FARTHER SOUTH...WINDS WILL NOT
BE AS STRONG (10-20 MPH WITH GUSTS TO 30 MPH)...SO HAVE OPTED TO
ISSUE AN SPS FOR INCREASED FIRE DANGER OVER THESE AREAS TO
HIGHLIGHT DRYING FUELS. 

DRY CONDITIONS (MIN RH VALUES 20-25%) WILL OCCUR AGAIN ON
THURSDAY. HOWEVER...WINDS ARE NOT EXPECTED TO BE AS STRONG. THIS
WILL LIKELY PRECLUDE THE NEED FOR ANY FIRE WX WATCHES/WARNINGS
OVER OUR AREA...EXCEPT FOR THE LOWER MD EASTERN SHORE WHERE WINDS
MAY REMAIN ELEVATED. HOWEVER, ANYONE PLANNING/INVOLVED IN OUTDOOR
BURNING ACTIVITIES SHOULD CONTINUE TO EXERCISE CAUTION. WILL
THEREFORE MENTION CONTINUED DRY CONDITIONS FOR TOMORROW IN THE
HWO/FWF.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...RED FLAG WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR 
     MDZ021>025.
NC...INCREASED FIRE DANGER FROM NOON EDT TODAY THROUGH THIS EVENING 
     FOR NCZ012>017-030>032.
VA...RED FLAG WARNING FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR 
     VAZ048-049-061>064-068>078-081>086-089>091-094-099-100.
     INCREASED FIRE DANGER FROM NOON EDT TODAY THROUGH THIS EVENING 
     FOR VAZ060-065>067-079-080-087-088-092-093-095>098.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THURSDAY FOR ANZ650-652-
     654-656-658.
     SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ633-
     635>637.
     SMALL CRAFT ADVISORY UNTIL 10 AM EDT THURSDAY FOR ANZ630>632-
     634.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ638.

&&

$$
SYNOPSIS...LKB/MAM
NEAR TERM...MAM
SHORT TERM...LKB/MAM
LONG TERM...SAM
AVIATION...LSA
MARINE...SAM
FIRE WEATHER...






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