MESOSCALE DISCUSSION 0856
   NWS STORM PREDICTION CENTER NORMAN OK
   0151 PM CDT SUN MAY 22 2011
   
   AREAS AFFECTED...CNTRL/ERN  IND...WRN/SRN OH...FAR NRN KY
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 221851Z - 221945Z
   
   AT LEAST A MARGINAL THREAT OF SEVERE HAIL/DAMAGING WIND AND PERHAPS
   A TORNADO IS EXPECTED THIS AFTERNOON. ALTHOUGH SEVERE STORM COVERAGE
   MAY REMAIN SPORADIC GIVEN AN ILL-DEFINED SYNOPTIC-SCALE FOCUS...A WW
   ISSUANCE WILL LIKELY BE NEEDED BY 20Z.
   
   A RECENT FLARE-UP IN TSTM ACTIVITY HAS OCCURRED ALONG AND N OF THE
   OH VALLEY. OVERALL ENVIRONMENTAL SETUP DOES APPEAR SLIGHTLY MORE
   MARGINAL RELATIVE TO AREAS WITHIN WW 324. NEVERTHELESS...A
   MODERATELY UNSTABLE AIR MASS CHARACTERIZED BY MLCAPE OF 1000 TO 2000
   J/KG AND MODERATE EFFECTIVE SHEAR OF 25 TO 35 KT...WILL SUPPORT
   OCCASIONAL UPDRAFT ORGANIZATION. GIVEN BROAD LARGE-SCALE ASCENT
   ASSOCIATED WITH THE UPPER MS VALLEY SHORT WAVE TROUGH...TSTM
   COVERAGE SHOULD CONTINUE TO INCREASE TOWARDS THE UPPER OH VALLEY.
   
   ..GRAMS.. 05/22/2011
   
   
   ATTN...WFO...PBZ...RLX...CLE...JKL...ILN...DTX...LMK...IWX...
   IND...
   
   LAT...LON   38678626 39648692 41198552 41658503 41818444 41778388
               40998295 40718268 39998170 39408166 38918196 38318233
               38098268 38548413 38548501 38678626