MESOSCALE DISCUSSION 0498
   NWS STORM PREDICTION CENTER NORMAN OK
   0700 PM CDT WED APR 20 2011
   
   AREAS AFFECTED...W-CNTRL AND NWRN TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 210000Z - 210100Z
   
   THUNDERSTORMS ORIGINATING FROM INITIAL LEFT SPLIT FROM EARLIER
   CONVECTION HAVE MAINTAINED STRONG REFLECTIVITY CHARACTERISTICS WITH
   N-NEWD PROPAGATION. ALTHOUGH THE BOUNDARY LAYER IS RELATIVELY STABLE
   IN THE WAKE OF A SFC COLD FRONT...STEEP MIDLEVEL LAPSE RATES GREATER
   THAN 8 C/KM HAVE SUPPORTED ADDITIONAL ELEVATED THUNDERSTORM
   DEVELOPMENT. GIVEN MUCAPE VALUES GREATER THAN 2000 J/KG...AND
   CLOUD-LAYER SHEAR OF 40+ KTS...A PRIMARY THREAT FOR LARGE HAIL WILL
   PERSIST FOR THE NEXT COUPLE HRS. DUE TO THE EXPECTED ISOLATED NATURE
   OF THUNDERSTORM COVERAGE...A WW IS NOT CURRENTLY ANTICIPATED.
   
   ..ROGERS.. 04/21/2011
   
   
   ATTN...WFO...FWD...OUN...SJT...
   
   LAT...LON   32509808 32079845 31839939 31829973 32069999 32340003
               32929979 33439932 33719882 33709826 33469785 33109781
               32509808