MESOSCALE DISCUSSION 0846
   NWS STORM PREDICTION CENTER NORMAN OK
   0742 PM CDT TUE MAY 28 2013

   AREAS AFFECTED...NE OH INTO NWRN/CNTRL PA

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

   VALID 290042Z - 290215Z

   PROBABILITY OF WATCH ISSUANCE...20 PERCENT

   SUMMARY...THE SEVERE WEATHER THREAT WITH ONGOING ISOLATED SUPERCELLS
   ACROSS PARTS OF NORTHEASTERN OHIO INTO NORTHWESTERN PENNSYLVANIA IS
   NOT EXPECTED TO PERSIST BEYOND ANOTHER HOUR OR SO.  A WATCH IS NOT
   CURRENTLY ANTICIPATED...BUT TRENDS WILL CONTINUE TO BE MONITORED.

   DISCUSSION...CONVECTIVE DEVELOPMENT...INCLUDING ISOLATED VIGOROUS
   THUNDERSTORM ACTIVITY...IS CURRENTLY IN THE PROCESS OF SHIFTING EAST
   OF THE LAKE ERIE REGION.  THIS IS WITHIN A BROADER ZONE OF LOW-LEVEL
   WARM ADVECTION EXTENDING DOWNSTREAM OF A SHORT WAVE
   IMPULSE...MIGRATING INTO THE GREAT LAKES REGION...ACROSS
   NORTHWESTERN AND NORTH CENTRAL PENNSYLVANIA.  WHILE THE BOUNDARY
   LAYER AIR MASS TO THE IMMEDIATE LEE OF LAKE ERIE...ACROSS
   NORTHWESTERN PENNSYLVANIA...HAD EARLIER BECOME WEAKLY TO MODERATELY
   UNSTABLE WITH DAYTIME HEATING...THIS INSTABILITY IS BEGINNING TO
   SUBSIDE WITH DIURNAL COOLING.  THIS...COUPLED WITH THE GRADUAL
   EASTWARD DEVELOPMENT OF CONVECTION INTO/ABOVE A RESIDUAL COOLER AND
   MORE STABLE LOW-LEVEL ENVIRONMENT ACROSS NORTH CENTRAL
   PENNSYLVANIA... SUGGESTS THAT SEVERE WEATHER POTENTIAL MAY BE
   CONFINED TO THE NEXT HOUR OR TWO BEFORE DIMINISHING.

   ..KERR/THOMPSON.. 05/29/2013


   ATTN...WFO...BUF...CTP...PBZ...CLE...

   LAT...LON   42038028 42217938 42107869 41977770 41307718 40587797
               40507831 41168029 41288092 42038028