FXUS61 KLWX 180305
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1105 PM EDT MON JUN 17 2013

.SYNOPSIS...
A WEAK COLD FRONT APPROACHING FROM THE NORTH WILL STALL OVER THE
MID ATLANTIC THROUGH TUESDAY...THEN MOVE SOUTH OF THE REGION EARLY
WEDNESDAY. AN AREA OF LOW PRESSURE WILL TRACK SOUTH OF THE AREA
TUESDAY NIGHT. HIGH PRESSURE WILL RETURN FOR THE REMAINDER OF THE
WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
CURRENT ANALYSIS THIS EVENING SHOWS A SURFACE TROUGH OVER THE
AREA WHILE A COLD FRONT REMAINS TO OUR NORTH OVER PENNSYLVANIA.
WEAK SHORTWAVE ENERGY IS ALSO MOVING THROUGH THE AREA THIS
EVENING.

THE WARM AND HUMID AIRMASS HAS CAUSED MODERATE AMOUNTS OF
INSTABILITY...DESPITE A MID-LEVEL CAPPING INVERSION.
ISOLATED/SCATTERED THUNDERSTORMS DEVELOPED DUE TO THE INSTABILITY AND
LIFT FROM THE SURFACE TROUGH...SHORTWAVE ENERGY...AND OUTFLOW
BOUNDARIES FROM PREVIOUS CONVECTION. ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS ARE EXPECTED LATE THIS EVENING...ESPECIALLY
EAST OF THE ALLEGHENY HIGHLANDS. LOCALLY HEAVY RAINFALL IS
POSSIBLE IN SOME OF THE STRONGER STORMS. MORE NUMEROUS SHOWERS AND
THUNDERSTORMS DEVELOPED OVER CENTRAL VIRGINIA ACROSS
AUGUSTA...ALBEMARLE AND NELSON COUNTIES. THIS WAS DUE TO OUTFLOW
BOUNDARIES AND TERRAIN CIRCULATION. SHOWERS AND THUNDERSTORMS HAVE
TRAINED OVER ONE ANOTHER...CAUSING A THREAT FOR FLASH FLOODING.
THIS ACTIVITY SHOULD DIMINISH OVERNIGHT.

THE COLD FRONT LOOKS TO RESIDE OVER THE CWA ON TUESDAY. A POTENT
SHORTWAVE WILL ALSO BE PASSING THROUGH THE AREA IN THE SOUTHWEST
FLOW ALOFT. SHOWERS AND THUNDERSTORMS WILL LIKELY BE MORE
WIDESPREAD TUESDAY...ESPECIALLY ACROSS THE CENTRAL AND SOUTHERN
PORTIONS OF THE CWA CLOSER TO THE SHORTWAVE. PLENTY OF CLOUDS MAY
HINDER DESTABILIZATION SOME...BUT MODELS SUGGEST 1-2K J/KG OF
CAPE. IF SHEAR WINDS UP BEING A LITTLE BETTER...THEN A FEW STORMS
COULD PRODUCE LOCALLY DAMAGING WIND GUSTS. THUNDERSTORMS WILL
CONTAIN HEAVY DOWNPOURS AND LOCALIZED FLASH FLOODING IS POSSIBLE
DUE TO HIGH RAINFALL RATES AND SATURATED SOIL FROM RECENT
RAINFALL.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
BOUNDARY IS FORECAST TO STALL OUT JUST SOUTH OF THE CWA TUESDAY 
NIGHT/WEDNESDAY. BOTH NAM/GFS INDICATE A WAVE OF LOW PRESSURE RIDING 
ALONG THE FRONT...SPILLING SOME SHOWERS TO THE NORTH INTO THE CWA. 
BUT THE MODELS DISAGREE WITH TIMING...WITH THE GFS BEING FASTER AND 
FAVORING A MOSTLY DRY WEDNESDAY WHILE THE NAM INDICATES SHOWERS. 

GIVEN TIMING UNCERTAINTY...AND BLENDING THE ECMWF IN THE MIX HAVE 
FOCUSED HIGHEST POPS ACROSS THE CWA TUESDAY NIGHT BUT CONTINUE 
CHANCE POPS INTO THE FIRST PART OF WEDNESDAY. WILL HAVE TO FINE TUNE 
TIMING AS WE GET CLOSER.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE BUILDS IN TO END THE WEEK...THEN MOVES OFFSHORE OVER 
THE WEEKEND. EXPECT DRY CONDITIONS MUCH OF THE TIME HOWEVER ISOLATED 
DIURNAL THUNDERSTORMS MAY BE POSSIBLE OVER THE HIGHER TERRAIN FRIDAY 
INTO THE WEEKEND. THERE MAY ALSO BE A SHORTWAVE SOMETIME LATE SUNDAY 
INTO MONDAY WHICH COULD BRING A CHANCE OF THUNDERSTORMS TO THE 
ENTIRE CWA. 

NEAR NORMAL TEMPERATURES AT THE END OF THE WEEK COULD MODERATE A 
LITTLE ABOVE CLIMO OVER THE WEEKEND INTO THE FIRST PART OF NEXT 
WEEK.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
ISOLATED SHOWERS AND THUNDERSTORMS WILL DISSIPATE OVERNIGHT. AREAS
OF BR/FOG WILL REDUCE VSBYS TO MVFR LEVELS AND POSSIBLY IFR LEVELS
LATE TONIGHT AND EARLY TUESDAY. THE BEST CHANCE FOR IFR VSBYS WILL
BE ACROSS KCHO WHERE THERE WAS RAINFALL THIS AFTERNOON AND
EVENING. A COLD FRONT WILL MOVE INTO THE TERMINALS TUESDAY AND
MORE WIDESPREAD SHOWERS AND THUNDERSTORMS ARE EXPECTED. A FEW
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING GUSTY WINDS AND LOCALLY
HEAVY RAINFALL.

COLD FRONT SAGS SOUTHWARD TONIGHT INTO TUESDAY. EXPECT MORE 
SCATTERED CONVECTION TUESDAY AND PERHAPS EVEN INTO WEDNESDAY UNTIL 
HIGH PRESSURE PUSHES THE FRONT FAR ENOUGH SOUTH FOR DRY WX.

&&

.MARINE...
NO SCA FLAGS EXPECTED IN THE NEXT 24 HOURS WITH RELATIVELY WEAK 
GRADIENT. WILL HAVE TO WATCH LOCALLY GUSTY WINDS IN THUNDERSTORMS 
LATE THIS EVENING AND AGAIN TUESDAY.

COLD FRONT MAKES IT WAY SOUTHWARD ACROSS THE WATERS ON 
TUESDAY...WITH A WAVE OF LOW PRESSURE RIDING ALONG THE FRONT TUESDAY 
NIGHT OR WEDNESDAY. HIGH PRESSURE BUILDS FOR THE END OF THE WEEK.

&&

.HYDRO...

AS TSTMS ARE WANING OVR ALBE/ROCK/NELSON WE HV TAKEN DOWN THE FLSH
FLD WRNG. BUT WHERE THE HVIEST RAFL HAS BEEN REPORTED/RDR
ESTIMATED WE HV ISSUED A FLD WRNG. JUST GOT OFF THE PHONE W/ ALBE
COUNTY - VDOT IS GOING OUT TO CLOSE CROZET AVE DUE TO HIGH WATER.
THIS IS EXPECTED OCCUR THRU SUNRISE.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
PRODUCTS...BJL/WOODY!