MESOSCALE DISCUSSION 0391
   NWS STORM PREDICTION CENTER NORMAN OK
   0212 AM CDT SAT MAR 31 2007
   
   AREAS AFFECTED...SOUTHEAST TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 310712Z - 310845Z
   
   THREAT OF AT LEAST ISOLATED SEVERE STORMS MAY PERSIST ACROSS PARTS
   OF SOUTHEAST TX EARLY TODAY. PARTS OF THE COASTAL PLAIN AND ADJACENT
   AREAS OF THE MIDDLE TX COAST MAY BE NEED TO BE INCLUDED IN A NEW
   WATCH SHORTLY.
   
   LATEST RADAR LOOPS INDICATES A PAIR OF LONG-LIVED SUPERCELLS MOVING
   ACROSS FRIO AND WILSON COUNTIES OF SOUTH-CNTRL TX. THESE STORMS HAVE
   A HISTORY OF PRODUCING HAIL AND HAVE SHOWN LITTLE SIGN OF WEAKENING
   OVER THE PAST COUPLE OF HOURS. THIS ACTIVITY APPEARS TO BE OCCURRING
   ON THE TRAILING SEGMENT OF AN OUTFLOW BOUNDARY THAT IS SITUATED
   AHEAD OF SYNOPTIC COLD FRONT FARTHER WEST. WHILE WARM SECTOR AHEAD
   OF ONGOING STORMS APPEARS WEAKLY CAPPED BASED ON LATEST RUC
   SOUNDINGS...VERY MOIST AND MODERATELY UNSTABLE AIR MASS WILL
   CONTINUE TO FUEL ONGOING STORMS...AND MAY SUPPORT ADDITIONAL
   DEVELOPMENT ALONG BOTH THE OUTFLOW BOUNDARY AND APPROACHING FRONT
   OVER THE NEXT SEVERAL HOURS.
   
   A MAJORITY OF LATEST AVAILABLE GUIDANCE SUPPORTS CONVECTIVE
   DEVELOPMENT ACROSS THE TX COASTAL PLAIN THROUGH 09-12Z TIME FRAME.
   IT IS UNCLEAR WHETHER THIS DEVELOPMENT OCCURS ON THE PREFRONTAL
   BOUNDARY OR THE SYNOPTIC FRONT. LARGE SCALE ASCENT ACROSS THE REGION
   SHOULD CONTINUE TO INCREASE WITHIN RIGHT-ENTRANCE REGION OF MID
   LEVEL JET STREAK DEVELOPING EWD ACROSS NRN TX. LOW LEVEL SHEAR
   ACROSS THE AREA OF CONCERN WILL BE MORE THAN SUITABLE FOR UPDRAFT
   ROTATION AND...IN ADDITION TO HAIL...IT APPEARS THAT AT LEAST
   ISOLATED TORNADO POTENTIAL...OR WIND DAMAGE THREAT...MAY INCREASE
   ACROSS THE REGION THROUGH DAYBREAK.
   
   ..CARBIN.. 03/31/2007
   
   
   ATTN...WFO...HGX...FWD...CRP...EWX...
   
   27749796 28029891 28379921 28529934 28879921 29169835
   29399811 29659791 29949771 30339767 30749737 31009701
   31269665 31009607 30609567 30199539 29769526 29259523
   29039525 28649559 28069652 27829729