FXUS61 KLWX 141948
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
248 PM EST MON DEC 14 2009

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A COLD FRONT WILL MOVE 
THROUGH THE MID ATLANTIC ON TUESDAY...USHERING IN A COLDER AND DRIER 
AIRMASS. HIGH PRESSURE WILL BUILD BACK OVER THE REGION FOR THE 
REMAINDER OF THE WEEK INTO THE WEEKEND. 
&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HIPRES WILL CONT TO MOVE OFF THE MID ATLANTIC COAST AS AN AREA OF 
LOPRES OVER THE UPPER MIDWEST MOVES THRU THE GREAT LAKES REGION 
TNGT. ASSOCIATED COLD FRONT SHOULD APPROACH THE APPALACHIANS BY 
DAYBREAK. 

MAIN CONCERN FOR TNGT WILL BE FOG POTENTIAL. WITH NO AIRMASS CHANGE 
FROM LAST NIGHT...ANOTHER ROUND OF FOG IS ANTICIPATED OVRNGT TNGT. 
INCREASING CLD COVER AND A LGT SLY WIND MAY PREVENT FOG FROM 
BECOMING AS WIDESPREAD/DENSE AS LAST NGT. HOWEVER...SUBSEQUENT SHIFT 
MAY NEED TO ISSUE A DENSE FOG ADVISORY IF DENSE FOG BECOME MORE 
WIDESPREAD THAN CURRENTLY FCSTD. WILL HIGHLIGHT IN HWO.

TEMPS SHOULD STAY ABOVE FREEZING ACROSS THE ENTIRE AREA...GENERALLY 
IN THE U30S ACROSS NRN MD TO M40S ALONG AND E OF I-95.
&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
LOPRES WILL TRACK ACROSS NRN NEW ENGLAND...DRAGGING A COLD FRONT 
THRU THE REGION. MODEL GUIDANCE CONSISTENT ON KEEPING 
MOISTURE/PRECIP HUNG UP ON THE WINDWARD SIDE OF THE MTS...KEEPING 
TUE DRY FOR MOST OF THE AREA. BEHIND THE FRONT...UPSLOPE SHOWERS 
WILL CHANGE TO SNOW SHOWERS ALONG THE WRN SLOPES OF THE ALLEGHENY 
AND POTOMAC HIGHLANDS...WHERE SOME LGT SNOWFALL ACCUMULATIONS ARE 
POSSIBLE DURING THE AFTN.

STRONG CAA ALOFT WILL ALLOW FOR GUSTY WNW WINDS TO MIX 
DOWN TO THE SFC DURING THE AFTN. DEPENDING ON EXACT TIMING OF 
FROPA...TEMPS MAY STRUGGLE TO RISE IN THE AFTN.
&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY NIGHT IN THE WAKE 
OF A COLD FRONT. UPSLOPE SNOW SHOWERS WILL BE LIKELY IN THE NW FLOW 
BEHIND THE SYSTEM...BUT THEY SHOULD CUT OFF EARLY WEDNESDAY. A QUICK 
INCH OR TWO OF SNOW IS POSSIBLE OVERNIGHT TUESDAY INTO WEDNESDAY 
ALONG THE WESTERN FACING RIDGES. HIGH PRESSURE REMAINS IN CONTROL OF 
THE SENSIBLE WEATHER THROUGH THE END OF THE WEEK. A WEAK LOW 
PRESSURE SYSTEM MAY MOVE THROUGH THE AREA ON FRIDAY...WHILE A COLD 
FRONT IS EXPECTED ON SUNDAY. 

HAVE KEPT THE FORECAST DRY FOR THE MID AND LATE WEEK...PRECIP 
CHANCES DURING THIS PERIOD LOOK TO SMALL TO MENTION AT THIS TIME. 
HOWEVER...HAVE INCLUDED SOME CHANCE POPS IN FOR SUNDAYS FRONTAL 
PASSAGE. 

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS FOR THE REST OF THIS AFTN. ANOTHER ROUND OF LOW 
STRATUS AND FOG IS POSSIBLE LATER THIS EVNG AND OVRNGT WITH MOISTURE 
REMAINING TRAPPED UNDERNEATH SUBSIDENCE INVERSION. SIMILAR TO LAST 
NGT...THE POTENTIAL FOR LIFR/VLIFR CIGS AND VSBYS WILL BE THERE.

NO CIG/VSBY RESTRICTIONS ARE ANTICIPATED THROUGH THE END OF THE 
WEEK. HOWEVER...SUB VFR CONDITIONS ARE POSSIBLE SUNDAY INTO EARLY 
MONDAY. NW WINDS WILL BE LIKELY THROUGH THE END OF THE WEEK...AND BE 
GUSTY AT TIMES.
&&

.MARINE...
WINDS WILL BE LGT THIS AFTN. SLY CHANNELING TNGT WILL INCREASE WINDS 
10-15 KT ACROSS THE CHSPK BAY BUT GUSTS SHOULD STAY UNDER SCA LVLS. 
A COLD FRONT MOVES THRU MIDDAY TUE WITH GUSTS WNW WINDS EXPECTED 
BEHIND THE FRONT. A SCA HAS BEEN POSTED FOR ALL MARINE ZONES 
BEGINNING 18Z TUE.

SMALL CRAFT CONDITIONS WILL LIKELY CONTINUE INTO TUESDAY NIGHT 
BEHIND THE COLD FRONT. NW WINDS ARE EXPECTED TO CONTINUE THROUGH THE 
END OF THE WEEK...AND REMAIN GUSTY AT TIMES. SMALL CRAFT CONDITIONS 
WILL BE POSSIBLE WEDNESDAY INTO THURSDAY. 
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM TUESDAY TO 7 AM EST WEDNESDAY 
     FOR ANZ530>543.

&&

$$
KLEIN/LISTEMAA