MESOSCALE DISCUSSION 0569
   NWS STORM PREDICTION CENTER NORMAN OK
   1252 PM CDT MON APR 25 2011
   
   AREAS AFFECTED...ERN OH...MUCH OF PA
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 251752Z - 251915Z
   
   SVR WEATHER THREAT IS EXPECTED TO INCREASE ACROSS ERN OH AND MUCH OF
   PA DURING THE NEXT FEW HOURS. A WW APPEARS LIKELY.
   
   MESOANALYSIS AT 17Z INDICATES A STATIONARY FRONT MAY BE RETREATING
   SLIGHTLY NWD ACROSS ERN OH/CNTRL PA AS WEAK SURFACE LOW PRESSURE
   OVER FAR ERN IND APPROACHES THE REGION. COOL/CLOUDY CONDITIONS EXIST
   N OF THE FRONT...WHILE CLEAR SKIES AND STRONG SURFACE HEATING /WITH
   TEMPERATURES CLIMBING THROUGH THE 70S/ IS OCCURRING S OF THE FRONT.
   IN ADDITION...DEWPOINTS IN THE IMMEDIATE VICINITY OF THE BOUNDARY
   RESIDE IN THE 50S TO LOW 60S. THOUGH MIDLEVEL LAPSE RATES ARE NOT
   PARTICULARLY STEEP...THE STRONG BOUNDARY LAYER DESTABILIZATION WILL
   AID IN BOOSTING MLCAPE VALUES TO 500-1500 J/KG BY PEAK HEATING. 
   
   VISIBLE SATELLITE IMAGERY SHOWS CUMULUS DEEPENING AND EXPANDING
   ALONG AND S OF THE FRONT DURING THE LAST HR OR SO...AND RADAR
   IMAGERY AND LIGHTNING DATA SHOW ISOLATED THUNDERSTORM INITIATION HAS
   TAKEN PLACE NE OF PIT. AS ADDITIONAL THUNDERSTORM DEVELOPMENT OCCURS
   DURING THE REMAINDER OF THE AFTERNOON...SVR WEATHER THREAT MAY
   BECOME SUFFICIENT FOR WW. VWP DATA INDICATES VERTICAL SHEAR PROFILES
   ARE SUFFICIENT FOR SUPERCELL DEVELOPMENT...WHICH WILL ENHANCE THE
   POTENTIAL FOR LARGE HAIL AND DAMAGING WINDS. IN ADDITION...LOW-LEVEL
   SHEAR WITH 0-1 KM SRH IN EXCESS OF 100 M2 S-2 MAY FAVOR A TORNADO OR
   TWO.
   
   ..GARNER.. 04/25/2011
   
   
   ATTN...WFO...PHI...BGM...BUF...CTP...PBZ...RLX...CLE...ILN...
   
   LAT...LON   41258247 41968046 42017683 41297565 40647605 40217678
               40337865 40028067 39298316 41258247