MESOSCALE DISCUSSION 0838
   NWS STORM PREDICTION CENTER NORMAN OK
   0353 PM CDT SAT MAY 21 2011
   
   AREAS AFFECTED...CNTRL TX
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 316...
   
   VALID 212053Z - 212200Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 316
   CONTINUES.
   
   TSTM CELLS CONTINUE TO INCREASE ALONG DRYLINE IN PORTIONS OF
   N-CNTRL/CNTRL TX. SPLITTING SUPERCELL CHARACTERISTICS HAVE BEEN
   NOTED IN RADAR TRENDS WHICH WILL REMAIN FAVORABLE FOR LARGE HAIL
   /SOME SIGNIFICANT/ GIVEN THE VERY UNSTABLE AIR MASS WITH MLCAPE OF
   3000 TO 4000 J/KG AND EFFECTIVE SHEAR OF 45 TO 50 KT. LOW-LEVEL
   WINDS HAVE DIMINISHED SLIGHTLY IN THE PAST FEW HOURS IN THE KFWS VAD
   WIND PROFILE WITH MODEST 0-1 KM SHEAR OF 15 KT. THIS SHOULD HELP
   LIMIT A MORE ROBUST TORNADO THREAT...BUT GIVEN THE DEGREE OF
   BUOYANCY...AN ISOLATED TORNADO CANNOT BE RULED OUT.
   
   CONVERGENCE ALONG THE DRYLINE REMAINS RATHER MODEST WITH SWRN EXTENT
   AS TOWERING CU FIELD APPEARS LESS AGITATED IN VISIBLE SATELLITE
   IMAGERY. AS SUCH...NEAR-TERM TSTM INITIATION MAY PROVE DIFFICULT S
   OF A JCT LATITUDE.
   
   ..GRAMS.. 05/21/2011
   
   
   ATTN...WFO...FWD...EWX...SJT...
   
   LAT...LON   31019872 32519784 32939766 33179705 33039654 32569658
               31669711 30569794 30249847 30259880 30349900 30539910
               31019872