FXUS61 KLWX 061438
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
938 AM EST MON FEB 6 2012

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA TODAY. A WEAK UPPER TROUGH
WILL CROSS THE AREA TONIGHT...THEN HIGH PRESSURE RETURNS ON TUESDAY. A
STRONGER UPPER TROUGH WILL PASS THROUGH THE REGION ON WEDNESDAY.
HIGH PRESSURE RETURNS THURSDAY. A COLD FRONT MOVING THROUGH THE
REGION BY THE END OF THE WEEK WILL MARK THE ARRIVAL OF A
SEASONABLY COLD AIRMASS THIS WEEKEND.

.NEAR TERM /THROUGH TONIGHT/...
DENSE FOG ADVISORY EXTENDED UNTIL 11AM FOR PATCHY BUT DENSE VALLEY
FOG THAT HAS PERSISTED FROM THE CUMBERLAND AREA DOWN TO
PETERSBURG WV. AREAS OF FOG ACROSS THE SOUTHERN SHENANDOAH VALLEY
AND A COUPLE VALLEYS TO THE WEST INTO HIGHLAND COUNTY VA PER
VISIBLE IMAGERY. TEMPERATURES ARE IN THE UPR 20S...SO FREEZING
FOG/HOAR FROST/BLACK ICE ON ROADS WILL CONTINUE THROUGH THE REST
OF THE MORNING UNTIL THE FOG BURNS OFF.

EXPECT PLENTY OF SUNSHINE WITH TEMPERATURES WARMING ABOVE CLIMO
BY 5 TO 10 DEGREES /MAX TEMPS LOW TO MID 50S/ UNDER A SOUTHWEST
FLOW.

HIGH PRESSURE WEAKENS/MOVES AWAY THIS EVENING. MODELS SHOW A MID 
LEVEL TROUGH SWINGING ACROSS THE CWA OVERNIGHT. TROUGH WILL BE 
MOISTURE-STARVED BUT MAY BRING SOME CLOUDS. WEAK SURFACE LOW ALSO 
FORMS ALONG THE CAROLINA COAST. LOOKS LIKE MOST OF THIS PRECIP 
REMAINS SOUTHEAST OF THE CWA. THEREFORE BACKED OFF ON/REMOVED POPS 
THAT WERE IN PLACE ACROSS THE SOUTHERN HALF OF THE CWA.

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UPPER SHORTWAVE TROUGH MOVES OFF THE NRN MID-ATLANTIC COAST TUE 
MRNG. SUBSIDENCE IN WAKE OF TROUGH AND UNDER THE INFLUENCE OF WEAK 
SFC HIPRES WILL RESULT IN DRY CONDITIONS ON TUE. TRENDED A FEW 
DEGREES WARMER THAN PREV FCST ON TUE WITH PLENTY OF SUNSHINE AND 
ADIABATIC COMPRESSION FROM DOWNSLOPING W-NW FLOW. MAX TEMPS SHOULD 
RISE INTO THE 50S JUST ABOUT EVERYWHERE EXCEPT IN THE MTS AND 
LOCATIONS NEAR THE MASON-DIXON LINE.

CLOUDS MOVE IN FROM THE WEST TUE NGT AS THE NEXT SHORTWAVE TROUGH 
AND ASSOCIATED COLD FRONT APPROACHES FROM THE MID MS RVR VLY. MODELS 
STILL DIFFER WITH TIMING OF THIS SYSTEM. HAVE LEANED SLIGHTLY MORE 
TOWARD THE FASTER GFS/NAM SOLUTIONS THAN THE SLOWER CANADIAN/ECMWF 
GIVEN LACK OF AMPLIFIED PATTERN. DID NOT INCREASE POPS MUCH FROM 
PREV FCST WITH THE CONTINUED MODEL DIFFERENCES. LGT PRECIP MAY 
OVERSPREAD THE POTOMAC HIGHLANDS LATE TUE NGT AS THE ULVL JET-STREAK 
STRENGTHENS OVER THE SERN AND MID-ATLANTIC STATES. THERMAL PROFILES 
WOULD BE COLD ENOUGH FOR SNOW TUE NGT. RA/SN MIX POSSIBLE ON WED FOR 
AREAS NORTH AND WEST OF I-95. BOUNDARY LAYER TEMPS MAY WARM ENOUGH 
BY WED AFTN FOR PRECIP TO BE ALL RAIN EXCEPT ACROSS THE POTOMAC 
HIGHLANDS AND NEAR THE MASON-DIXON LINE.

DESPITE HIPRES BUILDING IN FROM THE WEST...A TRAILING UPPER 
SHORTWAVE TROUGH MAY KEEP CLOUDS IN THE AREA WED NGT. SLGT CHANCE 
FOR SN SHOWERS WED NGT ALONG/WEST OF THE ALLEGHENY FRONT.

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIPRES EXPANDS EWD ACROSS THE MID-ATLANTIC STATES THU. 
EXTENDED-RANGE MODELS CONTINUE TO AMPLIFY LARGE-SCALE TROUGH ACROSS 
THE ERN CONUS DURING THE END OF THE WEEK AND WEEKEND. A COLD FRONT 
WILL MOVE THRU THE REGION FRI NGT INTO SAT. WITH A LACK OF SNOW 
COVER ACROSS THE REGION AND UPSTREAM AREAS...IT WILL BE HARD TO SEE 
MUCH BELOW NORMAL TEMPS AS CANADIAN AIRMASS WOULD BE MODERATED BY 
THE TIME IT GETS HERE.

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR WITH HIGH PRESSURE IN CONTROL. TROUGH WILL MOVE EAST THROUGH
TONIGHT. PASSAGE WILL BE DRY ACROSS THE TERMINALS...BUT WILL
RESULT IN 4-5 KFT CIGS AND A WIND SHIFT TO THE NORTHWEST AFT 06Z.

HIPRES WILL PROVIDE VFR CONDITIONS AND LGT WINDS TUE. A COLD FRONT 
WILL MOVE THRU WED. LGT RA MAY MIX WITH SN ACROSS NRN/WRN TERMINALS 
WED. ANY SN COULD LEAD TO A PERIOD OF IFR VSBYS AND SUB-VFR CIGS.

HIPRES RETURNS WED NGT AND THU BEFORE THE NEXT COLD FRONT MOVES THRU 
BY THE END OF THE WEEK.

.MARINE...
WESTERLY FLOW 5-10 KT BECOMES SLY TODAY AS HIGH PRESSURE OVER THE
REGION DRIFTS SOUTH. WEAK UPPER TROUGH CROSSES LATE TONIGHT.

LGT WINDS TUE. A COLD FRONT WILL MOVE THRU THE WATERS LATE WED. 
MARGINAL SCA CONDITIONS POSSIBLE LATE WED NGT INTO THU AS THE COLD 
FRONT MOVES OFF AWAY FROM THE EAST COAST AND HIPRES BUILDS IN FROM 
WEST.

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR MDZ502.
VA...NONE.
WV...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR WVZ050-055-
     502-504506.
MARINE...NONE.

SYNOPSIS...BAJ/JRK/BPP
NEAR TERM...BAJ/BPP
SHORT TERM...JRK
LONG TERM...JRK
AVIATION...BAJ/JRK/BPP
MARINE...BAJ/JRK/BPP