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000
FXUS61 KLWX 110757
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
357 AM EDT TUE JUN 11 2013

.SYNOPSIS...
A COLD FRONT WILL MOVE EAST OF THE CHESAPEAKE BAY REGION EARLY
THIS MORNING. HIGH PRESSURE BRIEFLY BUILDS IN THIS AFTERNOON
THROUGH EARLY WEDNESDAY. LOW PRESSURE IS THEN EXPECTED TO RIDE
ALONG A STATIONARY BOUNDARY OVER THE MID-ATLANTIC...IMPACTING THE
AREA LATE WEDNESDAY THROUGH THURSDAY NIGHT. HIGH PRESSURE
RETURNS FOR FRIDAY AND MAY HOLD INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
COLD FRONT WILL CONTINUE MOVING TO THE EAST ACROSS THE MID-
ATLANTIC/CHESAPEAKE BAY REGION OVERNIGHT/EARLY THIS MORNING.
UPPER TROUGH LAGS BEHIND THE SURFACE FRONT A BIT...AND WILL SWING
THROUGH DURING THE LATE MORNING AND EARLY AFTERNOON.

UNTIL THESE FEATURES MOVE THROUGH...WILL CONTINUE WITH A CHANCE OF
SHOWERS...MAINLY WITHIN THE PATH OF UPSTREAM ACTIVITY. AT 07Z...RADAR
SHOWED SOME SHOWERS HEADING TOWARD THE SOUTHWEST CWA DUE TO PVA AHEAD
OF A SHORTWAVE/VORT MAX. THIS WILL WILL LIKELY MOVE EAST THROUGH
DAYBREAK. MORE SHOWERS WERE COMING OFF LAKE ERIE AND MAY ROTATE
SOUTHEASTWARD THROUGH THE MORNING. 04Z RUN OF THE HRRR LOOKED
DECENT...AND HAVE FOLLOWED THIS TREND WITH TODAYS POP/WX FORECAST.

NVA/SUBSIDENCE BEHIND THE TROUGH MOVE IN LATER THIS
AFTERNOON/TONIGHT. THIS WILL END THE CHANCE FOR SHOWERS AND
PROMOTE CLEARING SKIES INTO THE EVENING HOWEVER IT LOOKS LIKE HIGH
MOISTURE WILL INCREASE OVERNIGHT IN W/NW FLOW ALOFT.

FOR TEMPERATURES...FAVORED A BLEND OF BIAS CORRECTED MAV/MET WHICH
FORECASTS MAXIMA/MINIMA NEAR CLIMO.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
ACTIVE WEATHER PATTERN IS EXPECTED LATE WEDNESDAY THROUGH THURSDAY
NIGHT. THERE ARE TIMING UNCERTAINTIES WITH INDIVIDUAL
WAVES...HOWEVER DURING THIS TIME THE MID-ATLANTIC WILL BE
VULNERABLE TO EXPERIENCING HEAVY RAINFALL/FLASH FLOODING AND
SEVERE WEATHER.

IT LOOKS AS IF A FRONTAL BOUNDARY WILL SINK SOUTHWARD INTO THE
MID-ATLANTIC DURING THE DAY WEDNESDAY...REMAINING OVER THE MID-
ATLANTIC REGION THROUGH THURSDAY UNTIL LOW PRESSURE BRINGS A COLD
FRONT THROUGH.

WITH W/NW FLOW IN PLACE...ANY UPSTREAM MESOSCALE CONVECTIVE SYSTEMS
COULD MOVE SOUTHEASTWARD INTO THE MID-ATLANTIC. THIS COULD HAPPEN
AS EARLY AS WEDNESDAY AFTERNOON/EVENING.

LATEST MODELS TREND LOW PRESSURE FURTHER NORTH WEDNESDAY NIGHT
INTO THURSDAY...PUSHING THE WARM FRONT INTO PENNSYLVANIA. LOCATION
OF LOW PRESSURE/WARM FRONT IS SOMEWHAT UNCERTAIN BUT IF THIS
OCCURS...CWA WOULD BE IN A WARM SECTOR FOR THURSDAY AS A COLD
FRONT APPROACHES. SO EVEN IF THE STORM TRACK FOR MCS ACTIVITY WERE
TO SHIFT A LITTLE TO THE NORTH...CWA WOULD STILL BE IN A POSITION
FOR SCATTERED TO NUMEROUS THUNDERSTORMS IN THE WARM SECTOR AND
AHEAD OF THE COLD FRONT THAT MAY PRODUCE FLASH FLOODING AND SEVERE
WEATHER /DAMAGING WINDS AND PERHAPS TORNADOES GIVEN THE FORECAST
SHEAR/.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE IS STILL FORECAST TO BUILD IN BEHIND THE FRONT ON
FRIDAY...AND CONTINUE INTO SATURDAY. GFS SHOWS THE NEXT SYSTEM
APPROACHING SUNDAY OR MONDAY WITH A CHANCE OF
SHOWERS/THUNDERSTORMS.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
PATCHY LOW CLOUDS /IFR/ WILL DISSIPATE THROUGH 09Z ACROSS THE
HUBS. COLD FRONT MOVES THROUGH EARLY THIS MORNING PROMOTING A WIND
SHIFT TO THE WEST. UPPER TROUGH LAGS...SO STILL COULD HAVE A FEW
SHOWERS INTO THE EARLY AFTERNOON...BUT PROBABILITY IS TOO LOW TO
MENTION IN TAFS ATTM.

WEAK HIGH PRESSURE BUILDS IN TONIGHT INTO EARLY WEDNESDAY. FRONTAL
BOUNDARY SINKS SOUTH INTO THE MID ATLANTIC WEDNESDAY NIGHT AND
COULD FOCUS SOME SHOWERS/THUNDERSTORMS. COLD FRONT MAY THEN BRING
STRONG THUNDERSTORMS THURSDAY.

&&

.MARINE...
SCA REMAINS IN EFFECT THROUGH THE REST OF THE NIGHT FOR THE LOWER
TIDAL POTOMAC/LOWER MD BAY AREA WITH NEAR 20 KT CONTINUING. EXPECT
THESE WINDS TO DIMINISH AFTER SUNRISE. COLD FRONT MOVES THROUGH
THE BAY AREA THIS MORNING.

WEAK HIGH PRESSURE BUILDS IN TONIGHT/EARLY WEDNESDAY BEFORE
ANOTHER FRONT SINKS SOUTH AND STALLS OVER THE WATERS BY WEDNESDAY
NIGHT. THIS FRONT MAY RETURN TO THE NORTH AS A WARM FRONT
THURSDAY...PROMOTING INCREASING SOUTHERLY WINDS WHICH MAY REQUIRE
A SMALL CRAFT ADVISORY. THUNDERSTORMS MAY ALSO PRODUCE STRONG
GUSTY WINDS THURSDAY BEFORE A COLD FRONT MOVES THROUGH.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
     ANZ533-534-537-543.

&&

$$
BPP