MESOSCALE DISCUSSION 1650
   NWS STORM PREDICTION CENTER NORMAN OK
   1218 PM CDT MON JUL 18 2011
   
   AREAS AFFECTED...NRN OH INTO WRN PA
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 181718Z - 181915Z
   
   STRONG TO SEVERE STORMS WILL CONTINUE/INCREASE EARLY THIS AFTERNOON.
   DAMAGING WINDS WILL BE THE MAIN THREAT WITH THESE STORMS AS
   LACKLUSTER LAPSE RATES KEEP THE HAIL THREAT TO A MINIMUM.
   
   16Z MESOANALYSIS INDICATED VERY WARM/MOIST AIR MASS WITH
   TEMPERATURES IN THE MID 80S TO LOW 90S ACROSS NRN OH INTO WRN PA.
   THIS HAS LEAD TO SBCAPE VALUES NEAR 2000 J/KG IN AN UNCAPPED
   ENVIRONMENT. PER LATEST WATER VAPOR IMAGERY...A VORTICITY MAX WAS
   ALSO EJECTING ACROSS LAKE ERIE AND WAS PARTLY RESPONSIBLE IN THE
   DEVELOPMENT OF THUNDERSTORMS ACROSS NWRN PA.  GIVEN A FAVORABLE
   DOWNSTREAM AIR MASS WITH DEWPOINTS IN THE UPPER 60S TO LOW 70S INTO
   CNTRL OH/PA AND EFFECTIVE BULK SHEAR VALUES OF 35-45 KT...STORMS
   SHOULD BE ABLE TO MAINTAIN STRONG TO SEVERE INTENSITY AS THEY TRACK
   SEWD INTO THE AFTERNOON HOURS. HOWEVER...SOME UNCERTAINTY EXISTS
   WITH REGARDS TO STORM COVERAGE/ORGANIZATION GIVEN MODEST UPPER LEVEL
   FORCING AND POOR LAPSE RATE ENVIRONMENT.
   
   ..LEITMAN.. 07/18/2011
   
   
   ATTN...WFO...CTP...PBZ...CLE...ILN...
   
   LAT...LON   41698340 41498382 41038387 40598370 40288334 40228267
               40158110 40137985 40487897 40877858 41257850 41617867
               41747892 41578016 41568126 41698340