MESOSCALE DISCUSSION 0942
   NWS STORM PREDICTION CENTER NORMAN OK
   0118 AM CDT FRI MAY 16 2008
   
   AREAS AFFECTED...SOUTH TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 160618Z - 160745Z
   
   TSTM ACTIVITY IS EXPECTED TO PERSIST AND OCCASIONALLY REACH SEVERE
   LEVELS ACROSS PARTS OF DEEP SOUTH TX THROUGH EARLY TODAY. A WATCH IS
   POSSIBLE FOR THE AREA.
   
   VERY MOIST AIR MASS/STRONG INSTABILITY WAS FOCUSED ALONG RESIDUAL
   FRONTAL ZONE SITUATED ACROSS THE LOWER RIO GRANDE VALLEY. ASCENT
   ACROSS THIS FRONT WAS BEING GENERATED/SUSTAINED BENEATH ENTRANCE
   REGION OF STRONG UPPER JET DOWNSTREAM FROM EXTENSIVE POSITIVE TILT
   TROUGH COVERING MUCH OF CNTRL U.S. ATTM. A WEAK MID-LEVEL SHORT WAVE
   TROUGH MAY ALSO BE SUPPORTING RECENT CONVECTIVE DEVELOPMENT NOW
   MOVING INTO STARR AND ZAPATA COUNTIES FROM NRN MEXICO...AS WELL AS
   ARC OF STORMS WITH SOME BOWING SEGMENTS SPREADING EAST TOWARD CRP
   AREA.
   
   GIVEN ABUNDANT INSTABILITY FEEDING THIS INTO ACTIVITY...AND
   FORECASTS OF CONTINUING ASCENT ACROSS THE REGION...THE THREAT FOR
   STORMS SHOULD PERSIST. ADDITIONALLY...WEAK POST-FRONTAL NLY/ELY FLOW
   WAS TOPPED BY STRONGER SWLY FLOW ALOFT RESULTING IN EFFECTIVE BULK
   SHEAR AROUND 50KT...MORE THAN ADEQUATE FOR STORM ORGANIZATION. LARGE
   HAIL AND SEVERE WIND GUSTS WILL BE POSSIBLE FROM SOME OF THE MORE
   INTENSE STORMS OVER THE NEXT FEW HOURS.
   
   ..CARBIN.. 05/16/2008
   
   
   ATTN...WFO...CRP...BRO...
   
   25789720 25679806 25839905 26459928 26889925 27699835
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