MESOSCALE DISCUSSION 1777
   NWS STORM PREDICTION CENTER NORMAN OK
   1213 PM CDT FRI AUG 17 2007
   
   AREAS AFFECTED...ERN PA THROUGH NJ
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 171713Z - 171845Z
   
   STORMS DEVELOPING OVER ERN PA CURRENTLY POSE A THREAT FOR MAINLY
   ISOLATED LARGE HAIL AND DAMAGING WIND. ACTIVITY IS VERY ISOLATED.
   HOWEVER...RECENT TRENDS SUGGEST STORMS MAY CONTINUE TO INCREASE IN
   COVERAGE. A WW MAY BE NEEDED SOON.
   
   THIS AFTERNOON A WARM FRONT EXTENDS FROM A SURFACE LOW IN CNTRL PA
   SEWD THROUGH SRN NJ. A COLD FRONT EXTENDS SWWD FROM THE LOW THROUGH
   SWRN PA. AN AXIS OF LOW LEVEL MOISTURE WITH DEWPOINTS IN THE UPPER
   60S EXISTS S OF THESE BOUNDARIES AND SURFACE HEATING OF THE MOIST 
   BOUNDARY LAYER HAS RESULTED IN MODERATE INSTABILITY IN WARM SECTOR
   OVER CNTRL THROUGH SERN PA AND SRN NJ. STORMS ARE DEVELOPING
   GENERALLY IN VICINITY OF THE WARM FRONT ACROSS PARTS OF E CNTRL PA
   AND MOVING EWD. STORMS MAY CONTINUE TO INCREASE IN COVERAGE WITHIN
   THE WEAKLY CAPPED ENVIRONMENT AS THE ATMOSPHERE DESTABILIZES. THE
   BOUNDARY LAYER MAY DESTABILIZE NEWD AS THE WARM FRONT SHIFTS EWD AND
   RICHER MOISTURE ADVECTS TOWARD THE MID ATLANTIC COAST.
   UNIDIRECTIONAL DEEP SHEAR OF 45 TO 50 KT WILL SUPPORT ROTATING
   STORMS WITH POTENTIAL FOR LEFT SPLITS WHICH MAY ENHANCE HAIL
   POTENTIAL.
   
   ..DIAL.. 08/17/2007
   
   
   ATTN...WFO...OKX...PHI...BGM...CTP...
   
   40787441 39887434 39447488 39807573 39747764 40327823
   41037771 41437671