MESOSCALE DISCUSSION 0518
   NWS STORM PREDICTION CENTER NORMAN OK
   0441 PM CDT FRI APR 30 2004
   
   AREAS AFFECTED...PARTS OF W CENTRAL TX...
   
   CONCERNING...SEVERE THUNDERSTORM POTENTIAL 
   
   VALID 302141Z - 302315Z
   
   TCU / CB DEVELOPMENT IS INDICATED ALONG ADVANCING COLD FRONT SOUTH
   OF TORNADO WATCH 132.  NEW WW MAY BE REQUIRED IN THE NEXT HOUR.
   
   LATEST DATA INDICATES SURFACE FRONT ACROSS PARTS OF W CENTRAL TX /
   THE TRANSPECOS REGION...WITH DRYLINE EXTENDING SWD FROM ITS
   INTERSECTION WITH THE COLD FRONT IN RUNNELS COUNTY.  
   
   WITH VERY STEEP LOW- TO MID-LEVEL LAPSE RATES AND 2000 TO 3000 J/KG
   MEAN-LAYER CAPE INDICATED ACROSS THIS REGION...WEAK CAPPING
   INVERSION WILL LIKELY CONTINUE TO BE BREACHED -- AT LEAST LOCALLY --
   ALLOWING SCATTERED STORMS TO DEVELOP SWD ALONG DRYLINE.  MOST LIKELY
   AREA FOR DEVELOPMENT WILL REMAIN NEAR DRYLINE / COLD FRONT
   INTERSECTION...WHICH WILL SHIFT PROGRESSIVELY SWD AS COLD FRONT
   CONTINUES ADVANCING.
   
   ALTHOUGH DEEP-LAYER SHEAR REMAINS SUPPORTIVE OF ORGANIZED /
   SUPERCELL STORMS...LOW-LEVEL SHEAR APPEARS TO BE WEAKER ACROSS THIS
   REGION THAN FURTHER NORTH.  THIS COMBINED WITH HIGHER LCLS WOULD
   SUGGEST THAT VERY LARGE HAIL AND LOCALLY DAMAGING WINDS WOULD BE THE
   PRIMARY THREATS.
   
   ..GOSS.. 04/30/2004
   
   
   ATTN...WFO...FWD...EWX...SJT...
   
   30960037 32279993 32409758 31509785 30339935 30530080