MESOSCALE DISCUSSION 0751
   NWS STORM PREDICTION CENTER NORMAN OK
   1143 PM CDT MON MAY 07 2007
   
   AREAS AFFECTED...SOUTH TX
   
   CONCERNING...TORNADO WATCH 253...
   
   VALID 080443Z - 080545Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 253 CONTINUES.
   
   STRONG THUNDERSTORM CLUSTERS JUST WEST OF THE RIO GRANDE HAVE
   FINALLY CONGEALED AND EVOLVED INTO A BOW ECHO.  THIS BOW IS NOW
   SURGING EWD ACROSS WEBB/ZAPATA COUNTIES WITHIN MODERATE INSTABILITY
   CHARACTERIZED BY STRONG ELY COMPONENT IN THE LOWEST 3 KM.  FORWARD
   PROPAGATION MAY ALLOW THIS ACTIVITY TO APPROACH THE COAST LATER THIS
   MORNING...THOUGH LIKELY IN A SOMEWHAT DEGRADED STATE.  IN THE SHORT
   TERM...IT APPEARS SEVERE THREAT MAY SPREAD EAST OF ONGOING WATCH
   INTO DUVAL AND MCMULLEN COUNTIES...JUST WEST OF THE CORPUS CRISTI
   AREA.  WATCH MAY NEED TO BE EXTENDED LOCALLY TO ACCOUNT FOR THIS
   SEVERE THREAT.
   
   ..DARROW.. 05/08/2007
   
   
   ATTN...WFO...LUB...MAF...CRP...BRO...
   
   32900364 34320202 34360060 33320039 32460157 31770363 
   
   28110016 28169807 27369775 26800004