Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 301059
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
659 AM EDT MON MAR 30 2015

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY CROSSES THE REGION THIS MORNING...WITH
HIGH PRESSURE RETURNING THIS AFTERNOON INTO TONIGHT. LOW PRESSURE
TRACKS ACROSS THE NORTHERN MID ATLANTIC TUESDAY WITH THE
ASSOCIATED COLD FRONT DROPPING THROUGH THE REGION TUESDAY NIGHT.
CANADIAN HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENT GOES WV IMAGERY SHOWS A MID-LEVEL TROUGH LIFTING NE OF THE
GREAT LAKES REGION...WITH A MID-LEVEL FRONTAL BOUNDARY TRAILING
BACK THROUGH THE OHIO VALLEY. AT THE SURFACE...LOW PRESSURE IS
CENTERED N OF THE GREAT LAKES...WITH HIGH PRESSURE OFF THE
SOUTHEAST COAST. THE SURFACE BOUNDARY (ASSOCIATED WITH THE COLD
FRONT ALOFT) CONSISTS MAINLY OF A WIND SHIFT FROM SW TO WNW.
LOCALLY...THE AIRMASS REMAINS RATHER DRY WITH DEWPOINTS RANGING
FROM THE UPPER TEENS TO LOW 20S...WITH TEMPERATURES IN THE UPPER
30S TO MID 40S. THE INITIAL BAND OF RADAR ECHOES THAT HAVE PASSED
ACROSS THE REGION HAVE AT MOST PRODUCED A BRIEF PERIOD OF -IP
ACROSS THE FAR NRN TIER COUNTIES. THE NEXT BATCH IS PASSING ACROSS
THE CENTRAL APPALACHIANS. THIS WILL PRODUCE ISO/SCT -SHRA OVER THE
NW HALF OF THE AREA THROUGH MID-MORNING. THE SURFACE AIRMASS WILL
REMAIN DRY THROUGHOUT SO EXPECT VERY LITTLE MEASURABLE QPE. THE
BOUNDARY IS EXPECTED TO ENCOUNTER SOMEWHAT BETTER MOISTURE OVER SE
VA/NE NC LATER THIS MORNING...SO A PERIOD OF LIKELY -SHRA HAS BEEN
MAINTAINED. STILL EVENTUAL QPE AMOUNTS ARE EXPECTED TO AVERAGE
~0.1IN OR LESS.

OTHERWISE...MOSTLY CLOUDY TO OVERCAST CONDITIONS THIS MORNING
SHOULD BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WITH THE
CLEARING TREND PROGRESSING NW-SE. FAVORABLE DOWNSLOPE FLOW (A WNW
WIND OF 10-15MPH WITH GUSTS TO AROUND 20MPH) SHOULD PUSH HIGHS
INTO THE LOW/MID 60S OVER INTERIOR VA/NE NC. FARTHER E...HIGHS
SHOULD BE IN THE MID/UPPER 50S WHERE CLOUD COVER WILL PERSIST
THROUGH EARLY AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDS ACROSS THE SOUTHEAST STATES TONIGHT AS LOW
PRESSURE MOVES INTO THE GREAT LAKES. A CLEAR AND SEASONABLY COOL
NIGHT IS EXPECTED WITH LOWS RANGING FROM THE UPPER 30S TO LOW 40S.

THE AFOREMENTIONED LOW PRESSURE SYSTEM DRIVEN BY ZONAL FLOW ALOFT
QUICKLY TRACKS ACROSS THE NRN MID ATLANTIC TUESDAY AFTERNOON.
EXPECT MOSTLY SUNNY CONDITIONS TO BEGIN THE DAY WITH INCREASING
CLOUDS ACROSS THE N BY AFTERNOON. A RIBBON OF 20-30% POPS (FOR
-SHRA) HAS BEEN MAINTAINED PRIMARILY FOR THE NRN INTERIOR VA
COUNTIES AND THE MD LOWER EASTERN SHORE DURING THE
AFTERNOON/EVENING HOURS. IT WILL BE DIFFICULT TO GET ANY PCPN S OF
THE LOW TRACK WITH DEEP LAYERED WSW FLOW.

LOW-LEVEL THICKNESS VALUES CONTINUE TO SUPPORT HIGHS AROUND 70F
ON TUESDAY OVER INTERIOR VA/NE NC. THIS IS CERTAINLY POSSIBLE WITH
LOW PRESSURE TRACKING N OF THE REGION RESULTING IN DEEP LAYERED
WSW FLOW. FORECAST HIGHS REMAIN IN THE UPPER 60S TO LOW 70S ACROSS
MUCH OF THE AREA...WITH MID 60S OVER THE INTERIOR ERN SHORE...AND
LOCALLY COOLER VALUES ALONG THE IMMEDIATE ATLANTIC COAST.

LOW PRESSURE EXITS THE DELMARVA AFTER MIDNIGHT TUESDAY NIGHT.
COOLER CONDITIONS ARE EXPECTED WEDNESDAY UNDER A SUNNY SKY AS
CANADIAN HIGH PRESSURE BUILDS INTO THE AREA. HIGHS ARE FORECAST TO
RANGE FROM THE LOW 50S ALONG THE COAST...TO THE UPPER 50S/LOW 60S
OVER INTERIOR VA/NE NC...AFTER MORNING LOWS IN THE UPPER 30S
N...TO MID 40S S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SPLIT FLOW CONTINUES TO BE PROBLEMATIC DURING THE EXTENDED
PERIOD...BUT MODELS CONTINUE TO COME INTO BETTER AGREEMENT WITH A
LATE WEEK FRONTAL PASSAGE. TO BEGIN THE EXTENDED...HIGH PRESSURE
PRESSURE SLIDES OFFSHORE WEDS NIGHT. INCREASING SLY FLOW ON THE BACK
SIDE OF THE DEPARTING HIGH AND A FLATTENING SRN STREAM WAVE WILL
PUSH A WARM FRONT THRU THE LOCAL AREA THURS. RESULTANT WAA WILL PUSH
TEMPS INTO THE LOW 70S INLAND AND LOW-UPPER 60S ERN SHORE AND
COASTAL AREAS. MODEL CONSENSUS IS TO KEEP THURS FRONTAL PASSAGE DRY
THANKS TO LIMITED MOISTURE AND A LACK OF APPRECIABLE FORCING. HAVE
REMOVED SLIGHT CHANCE POPS OVER THE PIEDMONT THURS. POTENT NRN
STREAM WAVE LOCATES OVER THE GREAT LAKES REGION THURS NIGHT-FRI
PUSHING AN ASSOCIATED/DEEPENING SFC LOW INTO SE CANADA. ATTENDANT
COLD FRONT PROGGED TO REACH THE CNTRL APPALACHIANS DURING THE LATE
THURS-FRI TIMEFRAME. GFS CONTINUES TO BE LESS AMPLIFIED WITH THE NRN
STREAM SYSTEM...PUSHING THE FRONT THRU THE REGION AROUND 12 HR
QUICKER THAN THE MORE AMPLIFIED/SLOWER ECMWF. REGARDLESS OF SPATIAL
AND TIMING DIFFERENCES...EXPECT INCREASING CHANCES FOR PRECIP
BEGINNING THURS NIGHT AND CONTINUING THRU SAT. 28/12Z ECMWF PUSHES
THE PRECIP OFFSHORE FRI NIGHT...BUT THE GFS STALLS THE FRONT OVER
THE REGION THROUGH SAT. HAVE MAINTAINED SLIGHT CHANCE TO LOW END
CHANCE POPS SAT TO ACCOUNT FOR UNCERTAINTY. MILD TEMPS EXPECTED
THURS NIGHT BEHIND THE WARM FRONT...WITH TEMPS GENERALLY IN THE LOW-
MID 50S. WARM SECTOR/SWLY FLOW PUSHES TEMPS INTO THE MID 70S INLAND
(POSSIBLY WARMER DEPENDING ON CLOUD COVER) AND UPPER 60S-LOW 70S ERN
SHORE AND COASTAL AREAS. COOLER SAT WITH HIGHS MID 60S INLAND AND
UPPER 50S-LOW 60S ERN SHORE AND COASTAL AREAS. HIGH PRESSURE PROGGED
TO BUILD OVER THE SE STATES SAT NIGHT-SUN...WITH DECREASING CHANCES
FOR PRECIP.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
MAINLY VFR THRU THE 12Z TAF PERIOD. AREA OF PCPN IS CURRENTLY
SLIDING E THRU CNTRL/ERN VA SO INCLUDED EITHER -RA OR VCSH IN ALL
TAFS THRU MIDDAY. CIGS ARE EXPECTED TO STAY PRIMARILY 4-7K
FT...BUT PSBLY DOWN TO MVFR HEIGHTS AT KECG LATER TDA. NO VSBY
RESTRICTIONS EXPECTED WITH ANY PCPN BEING LIGHT. SOME BREAKS IN
THE CLOUDS EXPECTED LATE TODAY AS A COLD FRNT CROSSES THE REGION.
THIS WILL SHIFT GUSTY S/SW WINDS THIS MORNG TO THE W/NW.

HIGH PRESSURE BUILDS BACK INTO THE SE US EARLY TUESDAY BUT A COLD
FRONT MOVING THROUGH THE AREA MAY BRING A FEW SHOWERS TO KSBY TUE
NIGHT. WED/WED NIGHT WILL BE DRY AS HIGH PRESSURE BUILDS IN FROM
THE NORTH.

&&

.MARINE...
LATEST SFC ANALYSIS REVEALS SFC HI PRES CENTERED OFF THE SE CST WITH
A COLD FRNT PUSHING EWRD THRU THE OH VALLEY. BETWEEN THESE TWO
FEATURES...A PREFRNTAL SLY SURGE IS NOW BEGINNING OVER THE LOCAL
WTRS. TRICKY CALL REGARDING SCA HEADLINES...BUT LOOKING AT CURRENT
WINDS AND EXPECTED SLIGHT INCREASE THRU THE FIRST HALF OF THE DAY TO
FREQUENT GUSTS ~20 KT...HOISTED A SCA FOR THE BAY AND LWR JAMES. A
SCA HAS ALSO BEEN ISSUED FOR THE NRN CSTL WTRS DUE TO SEAS OUT 20 NM
CLOSE TO 5 FT AND GUSTS UP TO ~25 KT. ONLY MARGINAL SCA CONDS
EXPECTED DUE TO WEAK WAA OVER COLD WATER PREVENTING THE HIGHEST
WINDS FM MIXING DOWN TO THE SFC. THE COLD FRNT CROSSES THE WTRS THIS
AFTN/EVENG...WITH SUB-SCA CONDS ANTICIPATED POST FRONTAL TONIGHT DUE
TO WEAK GRADIENT WINDS AND LIMITED CAA. HIGH PRESSURE BRIEFLY BUILDS
OVER THE WATERS LATE TONIGHT-TUES MORNING WITH THE FLOW SWITCHING
FROM THE NW BACK TO THE SW TUES. LOW PRESSURE AND AN ATTENDANT COLD
FRONT APPROACH THE WATERS TUES...CROSSING THE REGION TUES NIGHT. SCA
CONDITIONS ARE POSSIBLE POST FRONTAL TUES NIGHT-WEDS MORNING. BUT
AGAIN IT WOULD BE MARGINAL. HIGH PRESSURE RETURNS TO THE AREA WEDS-
THURS...RESULTING IN SUB-SCA CONDITIONS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EDT THIS AFTERNOON FOR
     ANZ630>632-634-638.
     SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ650-
     652.

&&

$$
SYNOPSIS...AJZ/BMD
NEAR TERM...AJZ
SHORT TERM...AJZ/BMD/JAO
LONG TERM...SAM
AVIATION...MAS
MARINE...MAS


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