Area Forecast Discussion
Issued by NWS Sterling, VA

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000
FXUS61 KLWX 280838
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
338 AM EST FRI NOV 28 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...THEN WILL MOVE
OFF THE COAST ON SATURDAY. A WARM FRONT IS EXPECTED TO LIFT TO THE
NORTH SATURDAY NIGHT. A COLD FRONT WILL THEN FOLLOW ON MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL TROUGH IS LOCATED ACROSS THE NORTHEAST CONUS THIS
MORNING. A SHORTWAVE TROUGH WILL MOVE ACROSS THE MID-ATLANTIC. HIGH
PRESSURE WILL APPROACH THE REGION TODAY AND NORTHWEST FLOW WILL
CONTINUE.

SNOW SHOWERS FROM A PASSING SHORTWAVE TROUGH WILL APPROACH THE
MID-ATLANTIC THIS MORNING. SOME IF NOT ALL OF THEM ARE LAKE INDUCED
FROM GREAT LAKES. LIGHT-MODERATE SNOW HAVE BEEN OBSERVED IN THIS
ACTIVITY ACROSS WESTERN PA. A WEAKENING TREND IS EXPECTED WITH THESE
SNOW SHOWERS AS THE SHORTWAVE TROUGH EXITS THE MID-ATLANTIC BY DAWN
TAKING THE LIFT NEEDED IN THE DENDRITIC GROWTH ZONE FOR HEAVIER SNOW
SHOWERS. LIGHT SNOW SHOWERS ARE POSSIBLE MAINLY WEST OF THE BLUE
RIDGE AND ACROSS NRN MD THROUGH DAWN. FLURRIES ARE POSSIBLE ACROSS
THE NORTHWEST SUBURBS OF BALTIMORE AND WASHINGTON DC.

FURTHER WEST...NORTHWEST FLOW AGAINST THE WESTERN SLOPES WITH A
MOISTURE FETCH FROM THE GREAT LAKES AND APPROACHING SNOW SHOWERS
WILL CAUSE MODERATE SNOW SHOWERS THIS MORNING. A WINTER WEATHER
ADVISORY IS IN EFFECT UNTIL 10AM FOR THE WESTERN SLOPES OF THE
ALLEGHENY FRONT AND 2-5 INCHES ARE EXPECTED BY MID MORNING.

HIGH PRESSURE ACROSS THE LOWER OHIO VALLEY IS APPROACHING THE
MID-ATLANTIC AND SUBSIDENCE WILL CUT OFF SNOW DEVELOPMENT BY LATE
MORNING. NORTHWEST FLOW WILL LEAD TO COOLER TEMPERATURES TODAY. FCST
MAX TEMPS WILL RANGE FROM THE 20S ACROSS THE MTNS TO THE MID 30S
NEAR THE MD/PA BORDER TO THE LOW 40S IN SOUTHERN MD. HIGH PRESSURE
WILL MOVE OVERHEAD TONIGHT LEADING TO DRY AND CALM CONDITIONS. FCST
MIN TEMPS WITH BE IN THE 20S.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
SHORTWAVE IN W/NW MID-LEVEL FLOW LOOKS TO STAY FAR ENOUGH NORTH TO
KEEP PRECIP UP IN PA SATURDAY MORNING. SREFS SUPPORTS THIS IDEA AND
THUS HAVE A DRY FORECAST. 00Z GFS TRIES TO SPREAD A LITTLE QPF SOUTH
OF THE MASON DIXON LINE /IT WOULD BE IN THE FORM OF SNOW/ SO BEARS
WATCHING BUT FEEL THAT QPF IS JUST A TAD TOO FAR SOUTH FROM THE GFS.

WITH SURFACE HIGH OFFSHORE...WARM ADVECTION CONTINUES THROUGH THE
WEEKEND. WARM FRONT LOOKS TO LIFT TO THE NORTH SATURDAY NIGHT OR
EARLY SUNDAY MORNING. IN THE WAKE OF ITS PASSAGE MAXIMA LIKELY ARE
ABLE TO RISE INTO THE MID TO UPPER 50S FOR MUCH OF THE CWA.
SOUTHEAST PORTIONS OF THE CWA SHOULD SEE SOME SUNSHINE BUT CLOUDS
ARE LIKELY TO BE STUBBORN ACROSS THE NORTHWEST CWA AND THERE WILL
ALSO BE A CHANCE OF RAIN SHOWERS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ABOVE NORMAL TEMPERATURES CONTINUE ON MONDAY...LIKELY A FEW DEGREES
HIGHER OVER SUNDAY/S MAXIMA. THERE WILL BE A COLD FRONT APPROACHING
IN THE MORNING...MOVING THROUGH IN THE AFTERNOON AND EVENING.
MOISTURE IS NOT IMPRESSIVE...NEVERTHELESS THERE WILL BE LOW POPS IN
THE FORECAST FOR RAIN SHOWERS MOST ESPECIALLY OUT WEST TOWARD THE
POTOMAC HIGHLANDS.

FRONT WINDS UP IN THE CAROLINAS ON TUESDAY AS HIGH PRESSURE BUILDS
IN FROM THE NORTH. COLDER AIR MOVES IN FOR TUESDAY. FRONT MAY ALSO
BE QUICK TO RETURN NORTH AS A WARM FRONT TUESDAY NIGHT INTO
WEDNESDAY BRINGING A CHANCE OF PRECIPITATION AGAIN.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT. NORTHWEST FLOW WILL
CONTINUE TODAY. NW WINDS 8-12KTS GUSTS UP TO 25 KTS ARE POSSIBLE
THIS AFTERNOON. HIGH PRESSURE MOVES OVERHEAD TONIGHT AND WINDS WILL
BECOME SOUTHERLY BY SAT MORNING.

HIGH PRESSURE BUILDS IN FOR FRIDAY THEN MOVES OFFSHORE FOR THE
WEEKEND. NO SIGNIFICANT WX IS EXPECTED. A COLD FRONT WILL MOVE
THROUGH LATER MONDAY.

&&

.MARINE...
NORTHWEST FLOW WILL CONTINUE ON THE WATERS AS HIGH PRESSURE
APPROACHES THE REGION TODAY. NW WINDS 10-15KTS WITH GUSTS UP TO
25KTS ARE EXPECTED THIS MORNING AS PRESSURE SURGE MOVES ACROSS THE
WATERS. WINDS WILL SLOWLY DIMINISH TODAY BUT STAY ABOVE SCA
CONDITIONS AND THEREFORE A SCA IS IN EFFECT THROUGH THE AFTERNOON..
HIGH PRESSURE MOVES OVERHEAD TONIGHT AND WINDS WILL BECOME SW-S BY
SAT MORNING

SOUTHERLY WINDS MAY GET CLOSE TO SCA CRITERIA UP THE CHESAPEAKE BAY
LATER SATURDAY AFTERNOON BUT CONFIDENCE TOO LOW TO ISSUE SCA ATTM.
SEEMS MORE LIKELY SATURDAY EVENING INTO THE NIGHT. COLD FRONT MOVES
THROUGH LATE MONDAY...POSSIBLY A NORTHERLY SURGE MAY PROMOTE SCA
CONDITIONS MONDAY NIGHT.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     MDZ501.
VA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     VAZ503.
WV...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     WVZ501-503-505.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HAS/BPP
NEAR TERM...HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...HAS/BPP
MARINE...HAS/BPP







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