MESOSCALE DISCUSSION 0752
   NWS STORM PREDICTION CENTER NORMAN OK
   0257 AM CDT THU MAY 12 2011
   
   AREAS AFFECTED...TX BIG BEND EWD TO SOUTH CENTRAL TX
   
   CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 
   
   VALID 120757Z - 120830Z
   
   WW WILL LIKELY BE NEEDED EARLY THIS MORNING FROM THE TX BIG BEND EWD
   INTO SOUTH CENTRAL TX WHERE TSTMS ARE EXPECTED TO DEVELOP AND EXPAND
   IN COVERAGE DURING THE NEXT FEW HOURS.  LARGE HAIL AND DAMAGING
   WINDS WILL BE THE PRIMARY THREATS.
   
   EARLY MORNING SURFACE ANALYSIS SHOWED AN AREA OF LOW PRESSURE
   LOCATED JUST W OF DRT IN NRN MEXICO...WITH THE PRIMARY BAROCLINIC
   ZONE EXTENDING ENEWD THROUGH SOUTH CENTRAL TX /JUST N OF BAZ/ AND
   THEN INTO SERN TX AND CENTRAL LA /ALONG AND S OF ONGOING STORMS IN
   THAT REGION/.  A WIND SHIFT EXTENDED SEWD FROM THE LOW TO THE TX
   COASTAL PLAIN BETWEEN CRP AND VCT.  THE AIR MASS ACROSS CENTRAL AND
   SRN TX IS STRONGLY UNSTABLE /MUCAPE 2000-4000 J PER KG/ AND
   SUFFICIENT EFFECTIVE BULK SHEAR /35-50 KT/ TO SUPPORT ORGANIZED
   STORMS.
   
   WATER VAPOR IMAGERY SHOWED A MIDLEVEL JET STREAK ADVANCING EWD
   ACROSS THE PERMIAN BASIN...WHILE IR AND RADAR IMAGERY INDICATED CU
   DEVELOPING ALONG THE PRIMARY BAROCLINIC ZONE TO THE N THROUGH NW OF
   DRT AND S OF SANDERSON TX NEAR THE INTERNATIONAL BORDER.  THIS IS
   LIKELY BEING SUPPORTED BY DCVA GLANCING THIS REGION FROM THE PERMIAN
   BASIN IMPULSE/JETLET.  GIVEN THE EARLY SIGNS OF UPDRAFTS AND
   AGREEMENT FOR ADDITIONAL DEVELOPMENT PER 05Z EXPERIMENTAL WRF-HRRR
   AND 00Z ECMWF...A WW WILL BE COORDINATED WITH THE AFFECTED WFOS
   EARLY THIS MORNING.
   
   ..PETERS.. 05/12/2011
   
   
   ATTN...WFO...CRP...EWX...SJT...MAF...
   
   LAT...LON   29880177 30230168 30970041 30759789 30229722 29069782
               28439875 28199926 28200012 28820057 29180076 29880177