MESOSCALE DISCUSSION 0271

MESOSCALE DISCUSSION 0271
   NWS STORM PREDICTION CENTER NORMAN OK
   0343 PM CDT FRI MAR 25 2011
  
   AREAS AFFECTED...NCNTRL/NERN TX...SCNTRL/SERN OK...SWRN AR AND
   EXTREME NRN LA
  
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
  
   VALID 252043Z - 252315Z
  
   LATEST VISIBLE SATELLITE IMAGERY DEPICTS A DEEPENING CUMULUS FIELD
   ACROSS THE WARM SECTOR OVER SCNTRL/SERN OK AND NCNTRL TX.
   HOWEVER...RIDGE/ANTICYCLONIC CHARACTER TO HIGH-LEVEL CLOUDS MOVING
   OVER THE REGION AND LACK OF SUBSTANTIAL LOW-LEVEL CONVERGENCE WILL
   PROBABLY BE DETRIMENTAL TO SURFACE-BASED CONVECTIVE INITIATION UNTIL
   AFTER 23Z OR SO.  THEREAFTER...WEAK HEIGHT FALLS ASSOCIATED WITH AN
   UPSTREAM TROUGH AND THE PRE-EXISTING WARM BOUNDARY LAYER MAY BECOME
   SLIGHTLY MORE FAVORABLE FOR INITIATION.  THERE APPEARS TO BE ENOUGH
   EVIDENCE TO SUPPORT LATEST RUC/GFS/NAM SOLUTIONS FOR AT LEAST
   ISOLATED THUNDERSTORMS NEAR THE TRIPLE POINT AND SWD ALONG THE
   DRYLINE FROM SCNTRL OK INTO NCNTRL TX NEAR SUNSET WHERE NRN-EXTENT
   OF 1000-1500 J/KG MLCAPES WILL EXIST.
  
   SHOULD A STORM FORM...ROUGHLY 45-50 KTS OF LARGELY UNIDIRECTIONAL
   DEEP-LAYER SHEAR AND MID-LEVEL LAPSE RATES IN EXCESS OF 7 DEG C PER
   KM WILL BE FAVORABLE FOR SPLITTING SUPERCELLS CAPABLE OF LARGE HAIL.
    A SUSTAINED SURFACE-BASED STORM EVOLVING ALONG/N OF THE RED RIVER
   NEAR A WARM FRONT COULD PRODUCE A TORNADO OR TWO...BUT THE HAIL RISK
   WILL DOMINATE.
  
   OTHERWISE...ADDITIONAL ACTIVITY IS EXPECTED TO EVOLVE AND/OR DEVELOP
   ALONG/N OF THE WARM FRONT AS ELEVATED ENTITIES OVER ERN OK AND CNTRL
   AR LATER THIS EVENING WITH POSSIBLE LARGE HAIL.