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...
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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.
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&& .NEAR TERM /THROUGH TONIGHT/...
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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.
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&& .SHORT TERM /SATURDAY THROUGH SUNDAY/...
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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.
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&& .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
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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.
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&& .AVIATION /08Z FRIDAY THROUGH TUESDAY/...
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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.
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&& .MARINE...
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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.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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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.
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&& $$ SYNOPSIS...HAS/BPP NEAR TERM...HAS SHORT TERM...BPP LONG TERM...BPP AVIATION...HAS/BPP MARINE...HAS/BPP

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