MESOSCALE DISCUSSION 0604
   NWS STORM PREDICTION CENTER NORMAN OK
   0708 PM CDT TUE APR 26 2011
   
   AREAS AFFECTED...PORTIONS SWRN/S-CENTRAL/NWRN OK...NW TX...ERN
   PANHANDLES OF TX/OK.
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 218...
   
   VALID 270008Z - 270145Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 218
   CONTINUES.
   
   SVR POTENTIAL ACROSS WW AREA...HOWEVER...MAY DIMINISH THROUGH
   REMAINDER EVENING WITH LOSS OF DIABATIC SFC HEATING AND RESULTANT
   CONTRIBUTIONS TO LOW-LEVEL LAPSE RATES.  POTENTIAL FOR ISOLATED LRG
   HAIL WILL CONTINUE FOR ANOTHER COUPLE HOURS WITH ACTIVITY FARTHER NW
   ACROSS PORTIONS TX/OK PANHANDLES...MOVING INTO NWRN OK.
   
   SFC MESOANALYSIS SHOWS COLD FRONT WELL S OF WW AREA -- FROM SRN
   PORTIONS DFW METROPLEX SWWD OVER NRN HILL COUNTRY THEN NWWD PAST
   ABI...BECOMING WARM FRONT NWWD INTO SFC LOW LOCATED OVER EXTREME
   N-CENTRAL TX PANHANDLE.  WARM FRONT SHOULD LIFT NEWD INTO SWRN OK
   THROUGH 06Z.  DEEP-LAYER ASCENT IN FORM OF BOTH DCVA AND ELEVATED
   WAA MAY REMAIN RELATIVELY MAXIMIZED JUST E AND NE OF THAT
   LOW...WHICH IS FCST TO MOVE SEWD ALONG WARM FRONT.  ERN PANHANDLES
   ARE CHARACTERIZED BY 250-700 J/KG MLCAPE ROOTED NEAR 700 MB BUT WEAK
   EFFECTIVE SHEAR...BASED ON MODIFIED RUC SOUNDINGS. MUCAPE WILL
   INCREASE WITH SEWD EXTENT ACROSS WRN OK AND NW TX...BUT SO WILL
   CINH...MAKING ADDITIONAL POTENTIAL VERY CONDITIONAL ACROSS CURRENT
   WW AREA.  DEPENDING ON INTERVENING CONVECTIVE TRENDS...WW MAY BE
   ALLOWED TO EXPIRE AS SCHEDULED AT 03Z...AND/OR AT LEAST PARTIALLY
   CLEARED BEFORE THEN.
   
   ..EDWARDS.. 04/27/2011
   
   
   ATTN...WFO...FWD...OUN...LUB...AMA...
   
   LAT...LON   33489793 33519989 35270057 35810171 36410187 36880099
               36809909 35809787 34759627 33969622 33789725 33489793