MESOSCALE DISCUSSION 0779
   NWS STORM PREDICTION CENTER NORMAN OK
   0455 PM CDT FRI MAY 13 2011
   
   AREAS AFFECTED...SOUTH TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 132155Z - 132330Z
   
   AN ISOLATED SEVERE THREAT CANNOT BE RULED OUT ACROSS
   SOUTH-CENTRAL/FAR SOUTH TX LATE THIS AFTERNOON/EARLY EVENING.
   
   A FEW TSTMS HAVE RECENTLY DEVELOPED ACROSS SOUTH-CENTRAL TX NEAR THE
   HONDO AREA JUST WEST OF SAN ANTONIO AS OF 2140Z....IN CLOSE
   PROXIMITY TO THE SURFACE COLD FRONT...WITH ADDITIONAL DEVELOPMENT
   ALSO NOTED ACROSS DEEP SOUTH TX TOWARD THE RIO GRANDE IN AREAS JUST
   NORTH/NORTHWEST OF MCALLEN. WITH SURFACE TEMPERATURES IN THE 90S
   F...A RELATIVELY HOT/MODESTLY MOIST AIRMASS IN PLACE ACROSS SOUTH
   TX...WITH MLCAPE VALUES ESTIMATED TO RANGE FROM 1500-3500 J/KG
   ACROSS THE WARM SECTOR. CURRENT THINKING IS THAT DEEP CONVECTIVE
   DEVELOPMENT WILL REMAIN RELATIVELY ISOLATED IN NATURE IN THE
   PRESENCE OF MODEST BACKGROUND FORCING FOR ASCENT...BUT AN ISOLATED
   SEVERE THREAT CANNOT BE RULED OUT GIVEN STEEP LAPSE RATES/AMPLE
   INSTABILITY IN CONJUNCTION WITH RELATIVELY STRONG MID/UPPER
   TROPOSPHERIC FLOW.
   
   ..GUYER.. 05/13/2011
   
   
   ATTN...WFO...CRP...EWX...BRO...
   
   LAT...LON   29469929 29259824 27919701 26299763 26359892 27999985
               28820001 29469929