Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 270118
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
918 PM EDT THU MAR 26 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION AND MOVE OFF THE COAST
OVERNIGHT THROUGH FRIDAY MORNING. AN UPPER LEVEL DISTURBANCE WILL
PASS THROUGH THE AREA LATER FRIDAY THROUGH SATURDAY NIGHT. HIGH
PRESSURE RETURNS FOR SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LATE THIS EVENG...LATEST RDR SHOWING ONLY SCTD SHOWERS AND AN
ISLTD TSTM JUST NNW OF OUR CWA JUST AHEAD OF AND ALONG A COLD
FRONT. SHOWERS WILL DEVELOP AND INCREASE IN COVERAGE FM NW TO SE
LATE TNGT INTO FRI MORNG...AS THE COLD FRONT SLIDES THRU THE
REGION. A COLDER AIRMASS WILL FILTER IN BEHIND THE COLD FRONT AND
A BRIEF PERIOD OF BREEZY NW WINDS WITH GUSTS UP TO 25 MPH SHOULD
BE ANTICIPATED. TEMPS ARE EXPECTED TO FALL INTO THE LWR 40S NW TO
THE LWR 50S SE BY MORNG.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
HIGH PRESSURE STARTS TO BUILD INTO THE MID ATLANTIC REGION FROM
THE NW ON FRI AS A DEEP UPPER LEVEL TROUGH DIGS INTO THE
AREA...CONTINUING TO BRING A MUCH COOLER AIRMASS INTO THE AREA.
HAVE LOWERED HIGH TEMPERATURES INTO THE MID-UPPER 40S BASED ON
THICKNESSES...MODEL TEMPERATURE TRENDS...AND CLOUDY SKIES IN
WIDESPREAD PRECIP (PROMOTING EVAPORATIVE COOLING) AS THE UPPER
TROUGH NOSES INTO THE MID ATLANTIC REGION. THERE WILL BE VERY
LITTLE DIURNAL TEMPERATURE CHANGES OCCURRING ON FRI AS A RESULT.
THERE IS PLENTY OF MOISTURE PRESENT AND INSTABILITY AVAILABLE IN
THE POST-COLD FRONT/UPPER TROUGH ENVIRONMENT TO HOLD ONTO
WIDESPREAD SHOWERS FRI MORNING WHICH WILL BECOME MORE FOCUSED
ALONG THE COAST BY FRI AFTN. MODEL CROSS SECTIONS SHOW MID-LEVELS
OF THE ATMOSPHERE DRYING OUT DURING THE AFTN WHILE SQUEEZING OUT
THE LAST BIT OF MOISTURE AVAILABLE FOR PRECIPITATION
GENERATION/SUSTAINABILITY. THE NAM IS MUCH FASTER THAN THE GFS IN
THIS CASE...HOWEVER THE INCOMING SHORTWAVE ENERGY ASSOCIATED WITH
THE UPPER TROUGH WILL PROVIDE THE BEST LIFT FOR CONTINUED SHOWER
ACTIVITY WITH THE REMNANT MOISTURE AVAILABLE DURING THE AFTN.
SHOWERS REALLY DIMINISH FRI EVENING/OVERNIGHT AND TEMPS DROP INTO
THE LOWER 30S NW (UPPER 20S POSSIBLE FOR FAR NWRN AREAS IN
LOUISA/FLUVANNA COUNTIES) AND THE MID-UPPER 30S SE. PRECIP-TYPE
WILL PRIMARILY BE IN THE FORM OF RAIN FRI NIGHT...HOWEVER SNOW (OR
GRAUPEL) COULD MIX WITH RAIN ON THE WRN FRINGE OF THE PRECIP
SHIELD WHERE THE COLDEST TEMPS WILL OCCUR. LITTLE TO NO
ACCUMULATIONS ARE ANTICIPATED AND IMPACTS TO TRAVEL ARE NOT
EXPECTED.

THE UPPER TROUGH MOVES DIRECTLY OVERHEAD ON SAT/SAT NIGHT AND SO
DO THE COLDEST TEMPERATURES ASSOCIATED WITH THIS AIRMASS. HIGHS
ONLY EXPECTED TO REACH INTO THE MID-UPPER 40S. IF THERE ARE ANY
LINGERING SHOWERS IN THE MORNING...THERE COULD STILL BE A MIX OF
RAIN AND SNOW ON THE WRN EDGES OF PRECIP. AFTN INSTABILITY WITH
THE TROUGH OVERHEAD WILL LIKELY RESULT IN WIDESPREAD CUMULUS WHICH
MAY RESULT IN ISOLATED SHOWERS THAT SHOULD STAY CONFINED ALONG THE
COAST. THERE COULD STILL BE SOME GRAUPEL MIXED WITH RAIN ACROSS
THE NRN NECK AND MD EASTERN SHORE DUE TO THE CONVECTIVE NATURE OF
THE PRECIP. ALL SHOWERS FINALLY COME TO AN END SAT EVENING...SKIES
CLEAR...AND TEMPERATURES PLUMMET INTO THE 20S BY SUN MORNING. SFC
HIGH PRESSURE MOVES ACROSS THE REGION ON SUNDAY. SUNNY SKIES WILL
BE THE MAIN WEATHER HIGHLIGHT BUT THE DRY/STABLE ENVIRONMENT WITH
LIGHT WEST WINDS WILL KEEP TEMPERATURES IN CHECK WITH READINGS
ONLY WARMING INTO THE MID-UPPER 40S ALONG THE IMMEDIATE COAST TO
THE LOWER 50S ACROSS INTERIOR VA AND ALL OF NE NC.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
OVERALL PATTERN WILL FEATURE SOME FLATTENING OF THE MID LEVEL
FLOW IN THE MEDIUM RANGE WITH A WEAKER VERSION OF A MEAN UPPER
RIDGE IN THE WESTERN CONUS AND AND TROUGH IN THE NE CONUS. WHAT
LOOKS TO BE A FAIRLY WEAK FRONT WILL PASS THROUGH THE REGION ON
MON. LATEST 12Z/26 ECMWF SHOWING A LITTLE MORE MOISTURE THAN THE
GFS AS IT DIGS THE SHORTWAVE FARTHER SOUTH. WILL HAVE A SLIGHT CHC
POP FOR SHOWERS FOR NOW...NO GULF CONNECTION PRESENT IN WNW FLOW
ALOFT SO ANY POTENTIAL QPF AMOUNTS LOOK FAIRLY LIGHT. TEMPERATURES
MON REMAIN SEASONABLE...HIGHS MAINLY IN THE 60S...A BIT COOLER
OVER THE ERN SHORE. NEXT SHORTWAVE SLATED FOR THE MIDDLE OF THE
WEEK WILL REMAIN FARTHER NORTH...MOVING FROM THE UPPER MIDWEST AT
12Z/TUE...TO OFF THE NEW ENGLAND COAST WED/WED NIGHT. THIS WILL
BRING DRY WX TO THE LOCAL AREA TUE/WED AS LOW LEVEL FLOW SHIFTS TO
THE SSW ON TUE...AND THEN TO THE W ON WED AS SFC LOW PRESSURE
PASSES ACRS THE GREAT LAKES AND NE CONUS. HIGHS MAINLY IN THE
60S...ALTHOUGH SOME LOWER 70S ARE POSSIBLE WELL INLAND DEPENDING
ON THE PRECISE TRACK OF THE SFC LOW. GFS/ECMWF DIVERGE BY
THU...GFS BEING THE WETTER SOLN AS SFC LOW PRESSURE APPROACHES
FROM THE TN VALLEY WITH HIGH PRESSURE OFF THE COAST. WILL HAVE CHC
POPS FOR NOW. TEMPERATURES WILL BE HIGHLY DEPENDENT ON CLOUD
COVER...STAYING NEAR CLIMO AT THIS POINT WITH HIGHS MAINLY IN THE
60S TO AROUND 70 F. MORNING LOWS MON-THU AVG IN THE UPPER 30S TO
UPPER 40S.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
THE CURRENT SURFACE ANALYSIS HAS A COLD FRONT EXTENDING FROM LOW
PRESSURE OVER EASTERN PENNSYLVANIA ACROSS CENTRAL VIRGINIA TO
ALABAMA. THE FRONT WILL MOVE THROUGH THE TAF SITES EARLY FRIDAY
MORNING. RAIN AND MVFR OR IFR CEILINGS WILL DEVELOP BEHIND THE
FRONT AND CONTINUE THROUGH MUCH OF THE DAY FRIDAY.

OUTLOOK...CONDITIONS SLOWLY IMPROVE LATE FRIDAY/FRIDAY NIGHT FRIDAY
AS THE WIND SHIFTS TO N/NW. ISOLATED RAIN AND SNOW SHOWERS ARE PSBL
SATURDAY. OTHERWISE...MAINLY DRY AND VFR CONDITIONS ARE EXPECTED TO
PREVAIL SATURDAY INTO EARLY NEXT WEEK.

&&

.MARINE...
CURRENT SFC ANALYSIS HAS SFC LOW PRESSURE OVER NRN VA/MD/SE PA...WITH
FAIRLY SIGNIFICANT PRESSURE FALLS OVER THE PAST 6 HR ON THE ORDER
OF 8 MB. THIS HAS ENABLED WIDESPREAD WINDS OF AROUND 20 KT ACRS
THE LOWER BAY AND COASTAL WATERS DESPITE THE MARINE INVERSION DUE
TO THE COLD WATERS. HIGHER GUSTS WERE OBSERVED EARLIER TODAY WITH
ENHANCEMENT FROM SHOWERS/EMBEDDED TSTMS.

A COLD FRONT TRACKS THROUGH THE REGION LATER TONIGHT...EVENTUALLY
BRINGING SCA CONDITIONS TO ALL AREAS AS MUCH COLDER AIR RUSHES IN
FROM THE NORTH. EXPECT WINDS TO SHIFT FROM THE SW TO THE N/NE
10-15KT...AND THEN INCREASE TO 20-25KT AS LOW-LEVEL CAA COMMENCES.
IT WILL TAKE AWHILE HOWEVER...AND WINDS WILL ACTUALLY TEND TO
RELAX A BIT THIS EVENING IN MANY AREAS. SCA`S WILL REMAIN IN
EFFECT ACRS THE COASTAL WATERS DUE TO ELEVATED SEAS...AND ACRS THE
LOWER BAY AND CURRITUCK SOUND (EVEN THOUGH SUB-SCA CONDITIONS MAY
PREVAIL FOR MUCH OF THE EVENING AND INTO THE EARLY AM HRS FRI).
WINDS FROM ABOUT 09Z THROUGH 15Z (DELAYED A FEW HRS FOR SRN
WATERS) WILL AVG 20-25 KT WITH GUSTS TO 30 KT ALONG THE COAST AND
BAY...TO A MORE MARGINAL 15-20 KT FOR THE RIVERS/SOUND.


WIND/WAVES/SEAS SUBSIDE FOR A SHORT PERIOD OF TIME LATER FRIDAY
AFTERNOON/EVENING...BEFORE ANOTHER ROUND OF MARGINAL SCA CONDITIONS
ARE POSSIBLE LATER FRIDAY NIGHT THROUGH SATURDAY NIGHT (DID NOT
EXTEND HEADLINES THIS FAR OUT AS THE SUB-SCA CONDITIONS HAVE A
GOOD CHC TO LAST > 6 HR). HIGH PRESSURE RETURNS SUNDAY AND MOVES
OFFSHORE SUNDAY NIGHT AHEAD OF ANOTHER COLD FRONT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 10 AM EDT FRIDAY FOR
     ANZ635>637.
     SMALL CRAFT ADVISORY UNTIL 4 PM EDT FRIDAY FOR ANZ632>634-650-
     652-654.
     SMALL CRAFT ADVISORY FROM 4 AM TO 1 PM EDT FRIDAY FOR ANZ630-
     631-638.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT FRIDAY FOR ANZ656-658.

&&

$$
SYNOPSIS...BMD/TMG
NEAR TERM...BMD/TMG
SHORT TERM...BMD
LONG TERM...LKB
AVIATION...DAP/LSA
MARINE...AJZ/LKB


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