MESOSCALE DISCUSSION 0728
   NWS STORM PREDICTION CENTER NORMAN OK
   0550 PM CDT MON MAY 17 2004
   
   AREAS AFFECTED...NWRN OH...NWRN PA...UPSTATE NY
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 211...
   
   VALID 172250Z - 180015Z
   
   ...THERE IS SOME POTENTIAL FOR ISOLATED DAMAGING WINDS WITH ACTIVITY
   MOVING ACROSS NERN OH INTO NWRN PA/UPSTATE NY. CURRENT THINKING IS
   WW WILL NOT BE EXTENDED DOWNSTREAM...
   
   THUNDERSTORMS HAVE LOOSELY ORGANIZED FROM CENTRAL PORTIONS OF LAKE
   ERIE...SWWD ACROSS ERN PORTIONS OF WW INTO CENTRAL OH. THIS
   ACTIVITY IS PROGRESSING STEADILY EWD INTO REGION CHARACTERIZED BY
   RELATIVELY STEEP LAPSE RATES...ON THE ORDER OF 8C/KM...BUT SOMEWHAT
   LESS BOUNDARY LAYER MOISTURE/INSTABILITY.  RELATIVELY DRY SUB CLOUD
   LAYER COULD ENHANCE DOWNBURST POTENTIAL THROUGH EARLY EVENING BEFORE
   DIURNAL COOLING LESSENS SEVERE THREAT. WW MAY NOT BE REQUIRED IF
   CONVECTION BEGINS TO WEAKEN AS ANTICIPATED.
   
   ..DARROW.. 05/17/2004
   
   
   ATTN...WFO...BUF...CTP...PBZ...CLE...
   
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