MESOSCALE DISCUSSION 0979
   NWS STORM PREDICTION CENTER NORMAN OK
   1055 AM CDT THU MAY 26 2011
   
   AREAS AFFECTED...CNTRL PA INTO UPSTATE NY
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 261555Z - 261730Z
   
   STRONG BOUNDARY LAYER HEATING IS OCCURRING OVER MUCH OF PA AND NY
   WELL AHEAD OF PRIMARY FORCING ASSOCIATED WITH UPPER TROUGH OVER THE
   OH VALLEY.  IN THE ABSENCE OF SIGNIFICANT CLOUD COVER IT APPEARS
   VERY STEEP LOW LEVEL LAPSE RATES WILL SOON CONTRIBUTE TO DEEP
   BOUNDARY LAYER THERMALS AND WITH TIME A MATURING CU FIELD THAT
   SHOULD LEAD TO SCATTERED THUNDERSTORM DEVELOPMENT...ESPECIALLY OVER
   THE HIGHER TERRAIN FROM CNTRL PA INTO UPSTATE NY. 
   ADDITIONALLY...DEEP LAYER SHEAR PROFILES FAVOR SUPERCELL DEVELOPMENT
   AND LOW LEVEL MOISTURE IS SUCH THAT ISOLATED TORNADOES MAY ACCOMPANY
   THE MORE ORGANIZED CELLS.  VERY LARGE HAIL MAY ALSO BE NOTED GIVEN
   THE INSTABILITY OBSERVED.  THIS ENVIRONMENT IS BECOMING INCREASINGLY
   FAVORABLE FOR SEVERE DEVELOPMENT AND A TORNADO WATCH MAY BE ISSUED
   BY 18Z.
   
   ..DARROW.. 05/26/2011
   
   
   ATTN...WFO...BTV...ALY...PHI...BGM...BUF...CTP...
   
   LAT...LON   40527795 43007688 44437458 43577343 41727518 40327654
               40527795