ZCZC SPCSWOMCD ALL
ACUS11 KWNS 022011 
SPC MCD 022011 
PAZ000-MDZ000-DCZ000-VAZ000-WVZ000-KYZ000-022145-

MESOSCALE DISCUSSION 1663
NWS STORM PREDICTION CENTER NORMAN OK
0311 PM CDT TUE SEP 02 2014

AREAS AFFECTED...ERN WV...NRN/WRN VA...MD...SERN PA...WASHINGTON DC

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 022011Z - 022145Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLATED STRONG TO LOCALLY SVR WIND GUSTS AND OCCASIONAL
INSTANCES OF HAIL WILL BE POSSIBLE THIS AFTERNOON ACROSS THE
MID-ATLANTIC INTO THE CNTRL APPALACHIANS. COVERAGE/MAGNITUDE OF THE
SVR THREAT APPEAR INSUFFICIENT TO WARRANT A WW...BUT TRENDS CONTINUE
TO BE MONITORED.

DISCUSSION...CONVECTIVE TRENDS SUGGEST A SLOW UPTICK IN TSTM
DEVELOPMENT ACROSS THE MID-ATLANTIC INTO THE CNTRL APPALACHIANS THIS
AFTERNOON...INFLUENCED BY LARGE-SCALE ASCENT ACCOMPANYING A
SHORTWAVE TROUGH MOVING THROUGH THE GREAT LAKES AND OH VALLEY. 
SFC OBS FROM 20Z INDICATE GENERALLY WEAK LOW-LEVEL CONVERGENCE
AMIDST NEARLY UNIFORM SWLY FLOW...WITH EXCEPTION TO A MORE
SUBSTANTIAL SLY COMPONENT NOTED OVER NW VA AND CNTRL MD...INVOF A
STRONG TSTM LOCATED NW OF WASHINGTON DC. RICH BOUNDARY LAYER
MOISTURE AMIDST STRONG HEATING /TEMPERATURES IN THE 80S-LOW 90S F/
IS YIELDING MLCAPE VALUES OF 1000-1500 J/KG...AND COMBINED WITH
EFFECTIVE SHEAR VALUES ESTIMATED AT 25-35 KT...THE ENVIRONMENT
REMAINS FAVORABLE FOR ORGANIZED TSTM CLUSTERS AND PERHAPS BRIEFLY
ORGANIZED DISCRETE STRUCTURES TO PERSIST THROUGH LATE AFTERNOON AND
EARLY EVENING. PRIMARY THREAT WILL BE ISOLATED STRONG-SVR WIND
GUSTS...WITH A LESSER THREAT FOR HAIL. COVERAGE/MAGNITUDE OF THESE
THREATS IS CURRENTLY EXPECTED TO REMAIN INSUFFICIENT FOR WW
ISSUANCE...BUT CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.

..ROGERS/HART.. 09/02/2014

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX...JKL...

LAT...LON   39737809 39927734 40367611 40287590 40007567 39697587
            39067651 37957791 37937805 37517979 37318040 37268165
            37548209 37888208 38178139 38668002 39097972 39637908
            39737809 

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