MESOSCALE DISCUSSION 0346
   NWS STORM PREDICTION CENTER NORMAN OK
   1035 PM CDT SUN MAR 25 2007
   
   AREAS AFFECTED...LWR TRANSPECOS...EDWARDS PLATEAU AND LWR CONCHO VLY
   OF SW TX
   
   CONCERNING...HEAVY RAINFALL 
   
   VALID 260335Z - 260530Z
   
   A HEAVY RAINFALL AND ISOLD SVR THREAT APPEAR TO BE INCREASING FROM
   THE LWR TRANSPECOS...WRN EDWARDS PLATEAU AND LWR CONCHO VLY OF SW TX
   OVERNIGHT.  MAIN SVR THREAT WILL BE ISOLD LARGE HAIL...BUT PRIMARY
   IMPACT WILL BE MERGING/TRAINING CELLS WITH PERSISTENT HEAVY RAINS.
   
   RECENT HEAVY RAINFALL THREAT OVER THE UPPER TRANSPECOS AND S PLAINS
   OF W TX APPEARS TO BE SHIFTING FARTHER SE THIS EVENING.  RECENT
   IR-SATL SHOWS RAPIDLY COOLING CLOUDS ASSOCD WITH TSTMS DEVELOPING IN
   NRN COAHUILA STATE IN MEXICO AND IN AREAS BOUNDED BY SANDERSON-SAN
   ANGELO-JUNCTION-DEL RIO LINE.  THIS DEVELOPMENT IS IN LINE WITH THE
   00Z NAM DEPICTION OF A CONCENTRATED QPF SIGNAL AND SEEMS TO BE
   DEVELOPING AMIDST INCREASING UPPER DIVERGENCE SHIFTING EWD IN TANDEM
   WITH THE UPPER LOW OVER CNTRL CHIHUAHUA.  THIS HAS CONTRIBUTED TO
   INCREASING ESELY LOW-LEVEL FLOW EVIDENT ON THE DEL RIO VWP /50 KTS
   AT H85/.  STRONG MOISTURE TRANSPORT ALONG THE NOSE OF THE ENHANCED
   FLOW WILL PROBABLY MAINTAIN TSTM GENERATION IN THE SAME AREA
   OVERNIGHT AS HIGHER PWAT AIR MASS SHIFTS NWWD.  AT THE SAME
   TIME...TSTMS WILL LIKELY CONTINUE FORMING ALONG THE APPROACHING COLD
   POOL FROM THE WEST.  THIS WILL RESULT IN NUMEROUS TSTM MERGERS AND
   HEAVY RAINFALL FOR SEVERAL HOURS. 
   
   A SECONDARY THREAT WILL BE THE POSSIBILITY FOR MARGINALLY SEVERE
   HAIL WITH THE STRONGER UPDRAFTS.  VERTICAL SHEAR WAS ENOUGH TO
   SUPPORT ORGANIZED STORMS...ESPECIALLY NEAR THE RIO GRANDE WHERE THE
   AFTERNOON BOUNDARY LAYER WARMED CONSIDERABLY.  THE THREAT IS
   SUFFICIENTLY LOW  THAT A CONVECTIVE WEATHER WATCH IS NOT NECESSARY
   ATTM.
   
   ..RACY.. 03/26/2007
   
   
   ATTN...WFO...EWX...SJT...MAF...
   
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