Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 312057
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
457 PM EDT FRI OCT 31 2014

.SYNOPSIS...
WEAK HIGH PRESSURE WILL SLOWLY DISSIPATE ACROSS THE REGION THROUGH
TONIGHT. A STRONG LOW PRESSURE SYSTEM WILL DEVELOP OFF THE MID
ATLANTIC COAST SATURDAY AND SATURDAY NIGHT BEFORE EXITING THE AREA
ON SUNDAY. HIGH PRESSURE RETURNS FOR THE BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST SURFACE ANALYSIS SHOWS WEAK HIGH PRESSURE OVER THE
PIEDMONT...WITH A 1005MB AREA OF LOW PRESSURE OFF THE NC OUTER
BANKS...WHICH HAS FORMED IN RESPONSE TO A SHORTWAVE TROUGH PUSHING
OFF THE SOUTHEAST COAST. A STRONGER SHORTWAVE TROUGH LAGS BACK OVER
THE SRN GREAT LAKES AND THIS WILL BECOME THE PRIMARY FEATURE INTO
SAT. THE LEADING WAVE WILL CONTINUE TO PULL TO THE NE TONIGHT...AS
THE STRONGER WAVE CONTINUES TO DIG SSE ACROSS THE LOWER OHIO VALLEY.
OVERALL DRY CONDITIONS ARE EXPECTED...WITH INCREASING MID/HIGH
CLOUDS (ONCE AFTERNOON CU DISSIPATE) AS THE LOCAL AREA REMAINS IN A
REGION OF SUBSIDENCE BETWEEN THE TWO SYSTEMS. 12Z HIGH-RES DATA DOES
INDICATE SOME MOISTURE COULD BACK INTO THE LOWER MD ERN SHORE LATE
TONIGHT SEEMINGLY RELATED TO A NE FETCH ASSOCIATED WITH A COLD
CONVEYOR BELT. A HIGH CHC TO LOW END-LIKELY (50-60%) PROBABILITY HAS
BEEN INCLUDED LATE TONIGHT TO ACCOUNT FOR THIS. TEMPERATURES SHOULD
DROP INTO THE LOW/MID 40S LATE THIS EVENING...WHICH SHOULD BE THE
EVENTUAL OVERNIGHT LOWS AS TEMPERATURES BECOME STEADY AFTER MIDNIGHT.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
THE OVERALL FORECAST SCENARIO REMAINS SIMILAR. A STRONG SHORTWAVE
TROUGH WILL DIG ACROSS THE TENNESSEE VALLEY TONIGHT AND ACROSS THE
CAROLINAS SAT. GOOD AGREEMENT CONTINUES WITH RESPECT TO A CLOSED
UPPER LOW FORMING OFF THE CAROLINA COAST MIDDAY SAT...WITH SURFACE
CYCLOGENESIS OFF THE OUTER BANKS SAT AFTERNOON/EVENING. THE SURFACE
LOW WILL QUICKLY LIFT TO THE NE LATER SAT NIGHT INTO SUNDAY...WITH
~1032MB SURFACE HIGH PRESSURE BUILDING IN FROM THE NW THROUGH SUN
NIGHT. THE AFOREMENTIONED AREA OF SUBSIDENCE SHOULD REMAIN OVER THE
AREA (WITH THE EXCEPTION OF THE ERN SHORE AND FAR SW PIEDMONT)
THROUGH MIDDAY SAT. THE CHC OF RAIN THEN INCREASES SAT AFTERNOON
ACROSS NE NC/SE VA AS THE LOW DEVELOPS OFF THE COAST. OVERALL QPF
AMOUNTS WILL BE MINIMAL AND GENERALLY LESS THAN 0.25IN. THE HIGHEST
AMOUNTS (0.25-0.50IN) SHOULD BE ACROSS THE ERN SHORE WHERE THE
DURATION OF RAIN SHOULD BE LONGEST.

A PERIOD OF STRONG NNE WIND (25-35 MPH WITH GUSTS TO ~45MPH) IS
EXPECTED ALONG COASTAL ZONES AS THE LOW DEEPENS OFF THE COAST AND
STRONG CAA COMMENCES. AREAS OF MINOR TIDAL FLOODING ARE POSSIBLE
ALONG THE ATLC BEACHES AND LWR CHES BAY (SEE COASTAL FLOODING
SECTION BELOW). A WIND ADVISORY MAY BE NEEDED OVER AT LEAST SOME OF
THE COASTAL ZONES SAT NIGHT FOR A 6-10 HOUR PERIOD. THIS WILL REMAIN
HIGHLIGHTED IN THE HWO AT THIS TIME.

RAIN WILL TAPER OFF SAT NIGHT WITH SUBSIDENCE IN THE WAKE OF THE
DEPARTING WAVE. THE SKY CLEARS OUT QUICKLY INTO SUNDAY MORNING
(ALTHOUGH A BAND OF SC COULD DEVELOP OFF THE BAY SUNDAY DUE TO THE
COOLER DRIER AIR ADVECTING OVER SSTS ~62-64F). THE SURFACE HIGH OF
CANADIAN ORIGIN SINKS FROM THE OHIO VALLEY INTO THE SOUTHEAST
BEGINNING SUNDAY. THIS WILL USHER IN THE COOLEST AIR OF THE SEASON
TO DATE. HIGHS SUNDAY SHOULD RANGE FROM AROUND 50 N/NE...TO THE MID
50S S. THE FIRST WIDESPREAD FREEZE OF THE SEASON SHOULD OCCUR LATE
SUN NIGHT/EARLY MON MORNING AS LOWS DROP TO 28-32 OVER THE INTERIOR
COASTAL PLAIN AND PIEDMONT. ENOUGH SFC PRESSURE GRADIENT WILL LIKELY
LINGER CLOSER TO THE COAST...WHICH WILL KEEP LOWS IN THE MID/UPPER
30S.

THE HIGH SHIFTS OFFSHORE MONDAY...WITH SSW FLOW RESUMING ACROSS THE
REGION. HIGHS SHOULD REBOUND INTO THE UPPER 50S/MID 60S UNDER A
MOSTLY SUNNY SKY.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE PERIOD CHARACTERIZED BY GENERAL MODERATION OF
TEMPERATURES TO BEGIN THE PERIOD AS HIGH PRESSURE SLIDES OFF THE
SOUTHEAST COAST TUESDAY/EARLY WEDNESDAY WITH RESULTANT
SOUTH-SOUTHWEST FLOW ALLOWING MAXIMA TO REBOUND INTO THE 60S TO
LOWER 70S TUESDAY AND WEDNESDAY, WITH EARLY MORNING LOWS MODERATING
BACK INTO THE 40S TO NEAR 50 WED AND THU MORNING.

ALOFT, UPPER PATTERN WILL BE CHARACTERIZED BY UPPER RIDGING, WHICH
WILL GRADUALLY BREAK DOWN AND SLIP OFFSHORE LATE WED/THU. NORTHERN
STREAM DISTURBANCE TRAVERSING THE CANADIAN PRAIRIES INTO THE UPPER
GREAT LAKES DURING THE MIDWEEK PERIOD, WITH THE ASSOCIATED WEAK
SURFACE FRONT DROPPING INTO THE AREA BY LATE WED NGT/THURSDAY. ONCE
AGAIN, THE BEST FORCING/DYNAMICS LOOK TO REMAIN CONFINED TO THE
NORTH/NORTHEAST. THEREFORE, SUSPECT THE FROPA WILL ONCE AGAIN HAVE
LITTLE MOISTURE WITH WHICH TO WORK. WILL KEEP POP NO HIGHER THAN 20%
FOR WED/THU...WITH ONLY A SLIGHT DROP OFF IN TEMPERATURE POST
FRONTAL LATE IN THE INTO THE 60S, WITH EARLY MORNING LOWS NEAR CLIMO
VALUES FRIDAY AND SAT MORNINGS.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
THE REGION IS BETWEEN SYSTEMS AT THE BEGINNING OF THE PERIOD WITH
SEVERAL WAVES OF LOW PRESSURE SLIDING ALONG A STALLED FRONT OFF
THE COAST WHILE A STRONG UPPER LEVEL DISTURBANCE CONTINUES TO MOVE
SEWD THROUGH THE OHIO VALLEY. AT THE MOMENT...SEEING LOTS OF
CU...3K - 5K FT...ACROSS THE REGION WITH LOW LEVEL NE FLOW PROVIDING
SOME ADDITIONAL MOISTURE...ESPECIALLY FOR COAST AREAS. MUCH OF
THIS CLOUD COVER SHOULD BEGIN TO DISSIPATE EARLY THIS EVENING ONCE
THE DAY TIME HEATING KICKS IN. THIS WILL LEAVE VFR CONDITIONS IN
PLACE FOR MUCH OF THE NIGHT. HOWEVER...LOW PRESSURE OFF THE NORTH
CAROLINA COAST WILL BEGIN TO DEVELOP OVERNIGHT AND INTO THE DAY ON
SATURDAY. THIS WILL STRENGTHEN THE ONSHORE FLOW AND CLOUDS WILL
DEVELOP AND LOWER TO MVFR TO IFR LEVELS TOWARD SUNRISE SAT AND
CONTINUING THROUGH THE DAY. EXPECT WINDS TO GRADUAL INCREASE
THROUGH 18Z TO AROUND 10 TO 15 KTS.

AFTER 18Z...CONDITIONS WILL CONTINUE TO DETERIORATE AS THE LOW
STRENGTHENS. WINDS WILL INCREASE TO 20 TO 30 KTS FOR COASTAL
SITES...EXPECT RIC...WITH MVFR TO IFR CEILINGS AND VISIBILITIES IN
THE RAIN REACHING IFR LEVELS. THE LOW WILL PULL AWAY FROM THE
COAST AFTER 6Z AND CONDITIONS SHOULD BEGIN TO IMPROVE BY 12Z...BUT
THE GUSTY NW WINDS WILL LINGER THROUGH THE DAY ON SUNDAY.
HOWEVER...ONCE THE STORM IS GONE...MONDAY THROUGH WEDNESDAY WILL
SEE HIGH PRESSURE WITH VFR CONDITIONS PREVAILING.

&&

.MARINE...
LATEST OBS REFLECT N-NE WINDS THIS AFTN 10-15KT. SURFACE LOW
PRESSURE HAS DEVELOPED ALONG THE STALLED COASTAL FRONT ORIENTED
OFFSHORE. WINDS HV INCREASED TO LOW END/MARGINAL SCA CRITERIA THIS
AFTN AND HAVE RAISED A SMALL CRAFT ADVY OVER THE LOWER BAY AND SOUND
THROUGH EARLY THIS EVENING. WINDS SHOULD DIMINISH FOR THE MID
EVENING HOURS INTO EARLY SAT AS SYSTEM PUSHES FARTHER NE AWAY FROM
THE AREA AND FARTHER OFFSHORE...TO A POSITION OFF OF THE NEW ENGLAND
COAST BY LATE TONIGHT.

WINDS WL BE RAMPING UP AGAIN TOWARDS SUNRISE SAT MORNING, AS LOW
PRESSURE DEVELOPS RAPIDLY NEAR HATTERAS. WINDS/WAVES/SEAS INCREASE
AS THIS LOW PRES STRENGTHENS OFF THE NC CST SATURDAY IN RESPONSE TO
A VERY POTENT MID-LEVEL SHORTWAVE TROF. SCA OVR NRN CSTL WTRS (ADDED
PARRAMORE TO CAPE CHARLES LGT TO EXISTING SCA) REMAINS IN EFFECT FOR
SATURDAY BEFORE THE GALE WARNING GOES INTO EFFECT SATURDAY NIGHT. A
PERIOD OF 5 FT SEAS IS EXPECTED OVER THIS AREA, WHILE CONDITIONS
ELSEWHERE OVER THE BAY AND LOWER JAMES LOOK TO DETERIORATE QUICKLY
ENOUGH SAT AFTN TO WARRANT GOING DIRECTLY TO THE GALE HEADLINE.

&&

.TIDES/COASTAL FLOODING...
LOW PRESSURE IS EXPECTED TO RAPIDLY STRENGTHEN OFF THE COAST LATE
SATURDAY AFTERNOON INTO EARLY SUNDAY MORNING. STRONG NNW WINDS ARE
LIKELY TO RESULT IN TIDAL DEPARTURES ON THE ORDER OF 1-2 FT ABOVE
NORMAL SATURDAY NIGHT ALONG THE ATLANTIC COAST AND LOWER BAY.
MINOR TIDAL FLOODING IS EXPECTED FOR THESE LOCATIONS AS THE SURGE
APPEARS TO COINCIDE WITH THE HIGH TIDE CYCLE SATURDAY NIGHT/EARLY
SUNDAY MORNING.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM EDT SATURDAY TO 11 PM EST
     SUNDAY FOR ANZ635>637.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633-
     634.
     GALE WARNING FROM 4 PM EDT SATURDAY TO 7 AM EST SUNDAY FOR
     ANZ630>634-638.
     SMALL CRAFT ADVISORY FROM 7 AM TO 4 PM EDT SATURDAY FOR ANZ650-
     652-654.
     GALE WARNING FROM 4 PM EDT SATURDAY TO 4 PM EST SUNDAY FOR
     ANZ650-652-654-656-658.

&&

$$
SYNOPSIS...AJZ/ALB
NEAR TERM...AJZ
SHORT TERM...AJZ/ALB
LONG TERM...MAM
AVIATION...ESS
MARINE...MAM
TIDES/COASTAL FLOODING...








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