FXUS61 KLWX 291959
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
259 PM EST SUN NOV 29 2009

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE EASTERN SEABOARD TONIGHT. A COLD
FRONT WILL MOVE ACROSS THE REGION ON MONDAY WITH SHOWERS. HIGH
PRESSURE RETURNS TUESDAY...BUT LOW PRESSURE WILL IMPACT THE REGION
WEDNESDAY INTO THURSDAY. CANADIAN HIGH PRESSURE WILL BUILD
OVERHEAD LATE IN THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
MULTIPLE BANDS OF WEAK SHOWER ACTIVITY DEVELOPING ACROSS THE UPPER 
MIDWEST AND MOVING EWD THIS AFTN. ACROSS THE MID ATLC...ONE OF THE 
MORE QUIET WX DAYS IN A WHILE. LIGHT AND RELATIVELY WARM SWLY WINDS 
HELPING TO BRING TEMPS INTO THE M-U60S /A FEW LOCALES EXPECTED TO 
TOP-OUT NEAR 70/...NOT TO MENTION MAINLY CLR SKIES. CONDITIONS WILL 
GRADUALLY CHANGE DURING THE NEXT SEVERAL HRS THOUGH...W/ MAINLY AN 
INCREASE IN CLOUD COVER THE STORY FOR THE EVENING-LATE NIGHT HRS.

THE UPPER TROF AXIS THAT/S RESPONSIBLE FOR THE RAIN SHOWERS ACROSS 
THE UPPER MIDWEST...WILL CONTINUE TO MOVE TOWARD THE REGION INTO 
EARLY MONDAY. A SFC LOW OVER SERN ONTARIO WILL CONTINUE TO 
STRENGTHEN...ALONG W/ THE ASSOCIATED COLD FRONT AS THE LOW MOVES NE. 
THE FRONT WILL MOVE ACROSS THE OHIO RVR VALLEY THIS EVENING AND INTO 
THE WINDWARD SIDE OF THE APLCNS OVERNIGHT...W/ DECENT FORWARD SPEED. 

OVERNIGHT LOWS NOT AS COLD TONIGHT /ACTUALLY ABOUT 10-15 DEG WARMER/ 
ESPECIALLY ACROSS THE MD/VA PIEDMONT...IN AREAS THAT DROPPED DOWN 
NEAR OR BELOW FREEZING LAST NIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
BY THE PRE-DAWN HRS MON...RAIN SHOWERS ARE EXPECTED TO BE PUSHING 
INTO THE POTOMAC HIGHLANDS AND THE ALLEGHENY FRONT. A WEAK 
PRE-FRONTAL BAND WELL AHEAD OF THE MAIN AREA OF SHOWERS...MAY MOVE 
THRU EARLY /11-14Z/ THOUGH THIS MAY END UP SCATTERING OUT AS IT 
MOVES INTO THE PIEDMONT. BY MID MORNING...A FAIRLY SOLID BAND OF 
RAIN SHOWERS WILL LIKELY BE PUSHING THRU THE AREA...INTO THE LATE 
MRNG AND EARLY AFTERNOON ACROSS THE ERN ZONES. BY MID AFTN...A BIT 
OF REDEVELOPMENT AND SLIGHTLY HIGHER QPFS FOR LOCALES NEAR THE BAY 
W/ A BETTER SLY MOISTURE SURGE AND INCREASED FORCING AS THE BASE OF 
THE UPPER TROF PUSHES INTO THE APLCNS AND HELPS STRENGTHEN THE LOW 
LEVEL WAA AREA JUST OFFSHORE. 

OVERALL THE QPF FOR THE MID ATLC REGION WILL BE LIGHT W/ THIS 
ACTIVITY...ESPECIALLY W/ A NE TO SW ORIENTED FRONT AND WEAK FORCING 
AND SFC MOISTURE CONVERGENCE. WITH THE CLOUDS AND PRECIP...TEMPS 
WILL BE MODERATED NOT ONLY FROM THE OVERNIGHT LOWS ONLY INTO THE 40S 
TONIGHT...SO HIGHS WILL PEAK INTO THE 50S ON MON AFTN.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
COLD FRONT AND ITS ASSOCIATED SHOWERS RAPIDLY MOVE OFF THE COAST 
EARLY MONDAY EVENING...ALLOWING FOR MUCH OF THE CWA TO DRY OUT. 
EXCEPTION WILL BE ACROSS THE HIGHLANDS WHERE AN UPSLOPE COMPONENT 
WILL ALLOW PRECIPITATION CHANCES TO LINGER. COLDER TEMPERATURES WILL 
MEAN A CHANGEOVER TO SNOW SHOWERS...AND THE MOST LIKELY TIME FRAME 
FOR LIGHT UPSLOPE ACCUMULATIONS ALONG FAVORED SLOPES LOOKS TO BE 
FROM 06Z TO 12Z TUESDAY. 

SURFACE HIGH PRESSURE BUILDS ACROSS THE MID ATLANTIC AND SOUTHEAST 
STATES ON TUESDAY...THEN MOVES OFF THE COAST TUESDAY NIGHT INTO 
EARLY WEDNESDAY. 

AS HAS BEEN ADVERTISED FOR DAYS...NEW LOW PRESSURE DEVELOPS IN THE 
GULF OF MEXICO ALONG THE TAIL END OF THE FRONT THAT MOVES THROUGH 
THE CWA MONDAY. LOW PRESSURE IS FORECAST TO TRACK NORTHWARD INTO THE 
MID ATLANTIC DURING THE MID WEEK. MODELS ARE CONVERGING ON A MORE 
INLAND SOLUTION WITH LOW PRESSURE TRACKING UP THE APPALACHIANS. 
REGARDLESS OF THE EXACT TRACK...LOW PRESSURE WILL BRING A RAIN EVENT 
TO THE CWA. CLOUDS WILL THICKEN UP WEDNESDAY...AND RAIN WILL START 
TO BREAK OUT IN THE AFTERNOON ACROSS THE SOUTHERN PORTION OF THE 
CWA. RAIN WILL THEN EXPAND NORTH TO INFILTRATE THE REMAINDER OF THE 
CWA DURING THE EVENING HOURS. CATEGORICAL POPS RESIDE ACROSS ENTIRE 
CWA WEDNESDAY NIGHT. RAINFALL TOTAL AOA AN INCH MAY RESULT. IN 
ADDITION...WITH A SLIGHTLY SLOWER EXODUS OF THE LOW/RAIN...POPS HAVE 
BEEN INCREASED ON THURSDAY MORNING BEFORE A DRY SLOT WOULD LIKELY 
WORK INTO THE CWA. 

IN THE WAKE OF LOW PRESSURE...ANOTHER ROUND OF UPSLOPE SNOW SHOWERS 
CAN BE EXPECTED THURSDAY NIGHT INTO FRIDAY. EAST OF THE MTNS SHOULD 
BE DRY...BUT PRESENCE OF AN UPPER TROUGH WILL LIKELY KEEP SOME 
CLOUDS AROUND. HIGH PRESSURE IS FORECAST TO BUILD BACK ON SATURDAY.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THRU EARLY MON. NO WX CONCERNS OVERNIGHT...ONLY 
MID-UPPER CLOUD DECKS STREAMING IN FROM THE WEST. S-SWLY WINDS WILL 
REMAIN LIGHT /5-10KT/ ACROSS THE MID ATLC...A THO A FEW LOCALES WILL 
INTERMITTENTLY GUST NEAR 15KT. EARLY MONDAY...CIGS WILL DROP TO NEAR 
MVFR AND BY MID MORNING...SCATTERED RAIN SHOWERS AND HI-END MVFR 
CIGS /2-3KFT/ WILL BE COMMON THRU AT LEAST EARLY AFTN. BY MID-LATE 
AFTN...MUCH OF THE ACTIVITY WILL BE PUSHING INTO THE CHESAPEAKE BAY 
REGION AND EVENTUALLY OFF THE COAST INTO THE EVENING HRS. SFC WINDS 
WILL STRENGTHEN AFTER THE COLD FRONT MOVES THRU /MID-LATE AFTN/ AND 
PICK UP FROM THE NW INTO 15-20KT RANGE.

NORTHWEST WINDS SETTLE IN BEHIND A COLD FRONT MONDAY NIGHT INTO 
TUESDAY. HIGH PRESSURE TUESDAY MOVES OFF THE COAST TUESDAY NIGHT 
INTO WEDNESDAY. LOW PRESSURE NEAR THE GULF COAST WILL LIFT NORTH 
INTO THE MID ATLANTIC WEDNESDAY NIGHT/THURSDAY. RAIN ASSOCIATED WITH 
LOW PRESSURE MAY LEAD TO IFR CONDITIONS WEDNESDAY NIGHT/THURSDAY.

&&

.MARINE...
A COLD FRONT WILL CROSS THE WATERS ON MONDAY AFTN/EVENING. THE SFC 
PRESSURE GRADIENT WELL AHEAD OF THE FRONT...WILL BEGIN TO STRENGTHEN 
OVER THE NEXT SEVERAL HRS ACROSS THE BAY. SCA CONDITIONS ARE 
EXPECTED FOR THE MIDDLE/LOWER PORTIONS OF THE BAY BEGINNING LATER 
THIS EVENING...LASTING THRU MUCH OF THE OVERNIGHT HRS. BY THE 
PRE-DAWN HRS MONDAY...WINDS WILL WEAKEN A BIT FOR MUCH OF THE BAY 
/EXCEPT THE LOWER MD BAY/...THEN PICK-UP AGAIN TOWARD LATE AFTN AND 
EARLY EVENING BEHIND THE COLD FRONT.

NORTHWEST WINDS WILL LIKELY BE IN SMALL CRAFT ADVISORY RANGE ACROSS 
MUCH OF THE WATERS MONDAY NIGHT...POSSIBLY LASTING INTO TUESDAY. 
WINDS SHOULD RELAX TUESDAY NIGHT INTO WEDNESDAY...BUT LOOK TO PICK 
BACK UP WEDNESDAY NIGHT INTO THURSDAY AS LOW PRESSURE MOVES ACROSS 
THE AREA.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EST MONDAY 
     FOR ANZ531>533-539>542.
     SMALL CRAFT ADVISORY FROM 6 PM MONDAY TO 6 PM EST TUESDAY FOR 
     ANZ530>533-538>542.
     SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST 
     TUESDAY FOR ANZ534-537-543.

&&

$$
SYNOPSIS...GMS/PELOQUIN
NEAR TERM...GMS
SHORT TERM...GMS
LONG TERM...PELOQUIN
AVIATION...GMS/PELOQUIN
MARINE...GMS/PELOQUIN