MESOSCALE DISCUSSION 0452
   NWS STORM PREDICTION CENTER NORMAN OK
   0739 AM CDT SUN APR 12 2009
   
   AREAS AFFECTED...SOUTHEAST TX INTO SOUTHERN LA
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 121239Z - 121345Z
   
   SURFACE BASED SEVERE POTENTIAL SHOULD STEADILY INCREASE THROUGH THE
   MID/LATE MORNING HOURS...WITH A RISK FOR TORNADOES IN ADDITION TO
   DAMAGING WINDS/HAIL ACROSS SOUTHEAST TX INTO SOUTHERN LA. A TORNADO
   WATCH MAY BE ISSUED SOON.
   
   SCATTERED ELEVATED CONVECTION HAS BEEN COMMON ALONG THE UPPER TX
   COASTAL PLAIN INTO LA EARLY THIS MORNING...AS A PRE-COLD FRONTAL
   BROKEN SQUALL LINE CONTINUES TO STEADILY PROGRESS EAST-SOUTHEASTWARD
   ACROSS THE TX HILL COUNTRY. IN ADDITION...A RECENT UPSWING IN
   DEVELOPMENT HAS BEEN NOTED IN THE GULF ABOUT 40 S OF BPT. AHEAD OF
   THE SQUALL LINE ASSOCIATED COLD POOL CROSSING TX...MODEST EARLY DAY
   HEATING AND STEADY INFLUX OF RICH LOW LEVEL MOISTURE IN TANDEM WITH
   NORTHWARD SPREADING WARM FRONT SHOULD LEAD TO AN UPSWING IN TSTM
   COVERAGE/VIGOR ACROSS SOUTHEAST TX INTO SOUTHERN LA BY MID/LATE
   MORNING...ALTHOUGH SOME CONCERNS DO REMAIN REGARDING THE DEGREE OF
   CAPPING AHEAD OF THE MAIN UPSTREAM LARGE SCALE FORCING PER 12Z CRP
   RAOB. REGARDLESS...GIVEN INCREASING SURFACE BASED DEVELOPMENT...A
   MOIST BOUNDARY LAYER/RATHER FAVORABLE KINEMATIC PROFILES WOULD
   SUPPORT SUPERCELLS CAPABLE OF TORNADOES...ALONG WITH DAMAGING
   WINDS/HAIL. A TORNADO WATCH WILL LIKELY BE COORDINATED SOON.
   
   ..GUYER.. 04/12/2009
   
   
   ATTN...WFO...LIX...LCH...SHV...HGX...
   
   LAT...LON   28729559 30199585 31209469 31269253 30659139 30049127
               29539150 29549365 28729559