MESOSCALE DISCUSSION 0827
   NWS STORM PREDICTION CENTER NORMAN OK
   0744 PM CDT THU MAY 14 2009
   
   AREAS AFFECTED...TX SOUTH PLAINS/TRANSPECOS REGION
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 150044Z - 150215Z
   
   CONVECTION DEVELOPING ACROSS THE TX TRANSPECOS REGION SHOULD EXPAND
   WITH TIME AS LOW-LEVEL SELYS INCREASE THIS EVENING.  ASSOCIATED
   SEVERE THREAT MAY WARRANT WW ISSUANCE.
   
   LATEST SATELLITE AND RADAR DATA REVEAL ISOLATED/DEVELOPING TCU/CB
   NEAR AND NE OF MIDLAND TX...WITHIN AIRMASS FEATURING MODERATE
   INSTABILITY ATOP A DEEPLY-MIXED BOUNDARY LAYER.  WHILE DEEP-LAYER
   SHEAR REMAINS FAIRLY WEAK...SOME INCREASE WILL OCCUR AS LOW-LEVEL
   SELYS INCREASE THIS EVENING BENEATH MODEST /AROUND 20 KT/ MID-LEVEL
   WLYS.  GIVEN THE DEGREE OF INSTABILITY AND SHEAR BECOMING AT LEAST
   MARGINALLY-SUPPORTIVE OF ORGANIZED/WEAKLY-ROTATING STORMS...SEVERE
   THREAT SHOULD INCREASE IN CONJUNCTION WITH INCREASING STORM
   COVERAGE.  WHILE DEEP MIXED LAYER AND ASSOCIATED EVAPORATIVE
   POTENTIAL COULD SUPPORT A LOCALLY-DAMAGING GUST OR TWO...THE MAIN
   THREAT WILL LIKELY BE LARGE HAIL -- PARTICULARLY LATER THIS EVENING
   AS THE BOUNDARY LAYER COOLS AND STORMS THUS BECOME ELEVATED WITH
   TIME.
   
   ..GOSS.. 05/15/2009
   
   
   ATTN...WFO...OUN...SJT...LUB...MAF...
   
   LAT...LON   31600188 32300248 33650170 34250082 33859942 33219931
               32289928 31630140 31600188