MESOSCALE DISCUSSION 2147
   NWS STORM PREDICTION CENTER NORMAN OK
   0236 PM CDT WED SEP 07 2011
   
   AREAS AFFECTED...SERN AND EAST CENTRAL PA INTO PARTS OF CENTRAL NJ
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 071936Z - 072100Z
   
   AN ISOLATED THREAT FOR A STRONG WIND GUST AND/OR A TORNADO CANNOT BE
   RULED OUT THE REST OF THE AFTERNOON FROM SERN PA INTO CENTRAL NJ. 
   GIVEN THE LIMITED SPATIAL EXTENT AND OVERALL THREAT CONCERN...A WW
   IS NOT ANTICIPATED.
   
   AFTERNOON MESOANALYSES INDICATED A WARM FRONT HAD MOVED INTO SERN PA
   AND EXTENDED NEWD FROM LANCASTER TO NRN BUCKS COUNTIES PA AND THEN
   ENEWD THROUGH CENTRAL NJ TO OFFSHORE THE SRN LONG ISLAND COAST. 
   STRONG SURFACE HEATING AND DEWPOINTS IN THE LOWER-MID 70S ARE
   RESULTING IN MLCAPE OF 1000-1200 J/KG WITHIN THE WARM SECTOR.  DEEP
   UNIDIRECTIONAL FLOW/SHEAR VECTORS ARE SUPPORTING PRIMARILY
   LINES/SHORT BOWING SEGMENTS AS INDICATED BY REGIONAL RADAR IMAGERY
   MOVING NEWD THROUGH SERN PA AT 1925Z.  BACKED SURFACE WINDS IN THE
   WARM SECTOR AND INVOF THE WARM FRONT ARE ALSO RESULTING IN ENHANCED
   LOW LEVEL SHEAR /EFFECTIVE SRH UP TO 200 M2 PER S2/ SUPPORTING LOW
   LEVEL STORM ROTATION AS HAS BEEN NOTED IN A STORM OR TWO THIS
   AFTERNOON OVER SERN PA.
   
   ..PETERS.. 09/07/2011
   
   
   ATTN...WFO...PHI...CTP...
   
   LAT...LON   39767592 40097588 40467595 40537502 40457428 40217412
               39867431 39777509 39707566 39767592