MESOSCALE DISCUSSION 0307
   NWS STORM PREDICTION CENTER NORMAN OK
   0559 PM CDT TUE MAR 29 2011
   
   AREAS AFFECTED...PORTIONS SW/S-CENTRAL TX...PRIMARILY SRN HILL
   COUNTRY AND EDWARDS PLATEAU TO MIDDLE RIO GRANDE VALLEY AND COASTAL
   BEND
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 73...
   
   VALID 292259Z - 300100Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 73
   CONTINUES.
   
   CONVECTIVE COVERAGE FCST TO INCREASE NEXT FEW HOURS ALONG/AHEAD OF
   SFC COLD FRONT OVER THIS REGION AS FRONT IMPINGES ON HIGHER-THETAE
   WARM SECTOR OVER S TX...LARGE HAIL AND OCNL DAMAGING GUSTS EXPECTED.
   
   
   LAST SFC MESOANALYSIS SHOWED COLD FRONT FROM NEAR GTU WSWWD ACROSS
   EDWARDS/VAL VERDE COUNTIES...AND CROSSING RIO GRANDE S OF
   6R6...MOVING SSEWD AT ABOUT 15 KT.  S OF FRONT...CONVECTION
   CONTINUES TO FORM OVER SERRANIAS DEL BURRO RANGE IN COAHUILA...BUT
   GENERALLY HAS BEEN WEAKENING AFTER MOVING E OF MOUNTAINS AND AWAY
   FROM OROGRAPHIC FORCING SOURCE.  STILL...CINH MAY BE WEAK ENOUGH TO
   ALLOW ONE OR TWO SUCH TSTMS TO ACQUIRE SUSTAINED ROTATION AND REACH
   RIO GRANDE AFTER 00Z...ESPECIALLY ANY LEFT-MOVERS OR BOWS THAT MAY
   FORM.  DEEP-LAYER VERTICAL WIND PROFILES REMAIN FAVORABLE WITH 40-50
   KT EFFECTIVE SHEAR.  PRONOUNCED COUNTERCLOCKWISE CURVATURE IN
   PREFRONTAL/LOW-LEVEL HODOGRAPHS...BOTH AS OBSERVED IN DFX VWP AND AS
   PREDICTED REASONABLY WELL BY RUC FCST SOUNDINGS...YIELDS FAR MORE
   NEGATIVE THAN POSITIVE SRH FOR ALL BUT EXTREMELY DEVIANT/FAST
   RIGHT-MOVERS...WHICH ARE UNLIKELY EXCEPT WHERE OUTFLOW-DOMINANT.
   
   ADDITIONAL TSTMS DEVELOPING N OR NE OF MEX MOUNTAINS MAY BE UNDERCUT
   BY ZONAL SEGMENT OF COLD FRONT SOON THEREAFTER...AS HAS ISOLATED
   CELL OVER VAL VERDE COUNTY.  CONVECTION APPEARS TO BE DEEPENING
   FARTHER ENE ALONG MORE SW-NE ALIGNED FRONTAL SEGMENT FROM
   EDWARDS-LLANO COUNTIES AS OF 2230Z.  THIS ACTIVITY MAY HAVE ACCESS
   TO WARM-SECTOR AIR MASS FOR MORE SUSTAINED PERIOD...ESPECIALLY ANY
   TSTMS THAT CAN AVOID ACQUIRING LEFT-MOVING SUPERCELLULAR
   CHARACTERISTICS AND MOVE EWD/SEWD AT LEAST IN STEP WITH BOUNDARY
   TRANSLATION.  MOST STORM MOTIONS NEAR FRONT SHOULD BE CLOSE TO
   HODOGRAPH...WITH FRONTAL FORCING EVENTUALLY CONTRIBUTING TO DOMINANT
   QUASI-LINEAR CONVECTIVE MODE.
   
   ..EDWARDS.. 03/29/2011
   
   
   ATTN...WFO...HGX...CRP...EWX...BRO...
   
   LAT...LON   27279741 27279948 27579950 27669967 27789985 27979995
               28160010 28270032 29120068 29150080 29260078 29750141
               29770176 30190094 30259699 28189666 27709713 27439731
               27279741