MESOSCALE DISCUSSION 0547
   NWS STORM PREDICTION CENTER NORMAN OK
   0540 PM CDT MON APR 23 2007
   
   AREAS AFFECTED...PORTIONS SW TX.
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 232240Z - 240045Z
   
   OROGRAPHIC FORCING AND UPSLOPE ADVECTION OF HIGH THETAE AIR HAS
   CONTRIBUTED TO DEVELOPMENT OF WIDELY SCATTERED TSTMS OVER SERRANIAS
   DEL BURRO REGION OF NRN COAHUILA.  THIS ACTIVITY HAS DEVELOPED UNDER
   BREAK IN HIGH CLOUDS WHICH IS SHIFTING NEWD ACROSS ADJACENT PORTIONS
   OF SW TX...AND WHICH WILL ALLOW ADDITIONAL/FAVORABLE DESTABILIZATION
   OF BOUNDARY LAYER.  OTHER DEVELOPMENT MAY OCCUR ALONG SRN PORTION OF
   DRYLINE...WHICH WAS ANALYZED AT 22Z OVER EXTREME WRN CROCKETT...ERN
   PECOS AND TERRELL COUNTIES.  MAIN THREAT IS COMBINATION OF DAMAGING
   HAIL AND SVR GUSTS.
   
   ACTIVITY OVER THIS REGION ALSO MAY BECOME SEEDED BY THICK HIGH
   CLOUDS AND/OR NEARBY STORMS...LEADING TO MESSY MIXED MODES INCLUDING
   HEAVY-PRECIP SUPERCELLS...SPLITTING STORM POTENTIAL...AND ALSO
   SMALL/BOWING LINE SEGMENTS.  STRONG MID/UPPER JET WINDS AHEAD OF
   EJECTING MEX SHORTWAVE TROUGH WILL MAINTAIN FAVORABLE DEEP-LAYER
   BULK SHEAR...I.E. 60-70 KT EFFECTIVE SHEAR.  INITIAL WEAKNESSES IN
   LOW LEVEL HODOGRAPHS ARE EVIDENT BECAUSE OF AREAS OF 10 KT FLOW
   BETWEEN 1-2 KM AGL...EVIDENT IN DFX VWP AND IN RUC FCST SOUNDINGS. 
   HODOGRAPHS SHOULD ENLARGE AFTER DARK FOR ANY REMAINING
   CONVECTION...HOWEVER...AS LLJ STRENGTHENS.  70 DEG F SFC DEW POINT
   AT UVA AWOS SITE IS BOGUS...HOWEVER MID-UPPER 60S F FARTHER E AND S
   ARE NOT...AND SHOULD SPREAD NWWD ACROSS THIS REGION THROUGH EVENING
   HOURS.  THIS WILL CONTRIBUTE TO MLCAPES 2500-3000 J/KG.
   
   ..EDWARDS.. 04/23/2007
   
   
   ATTN...WFO...CRP...EWX...SJT...MAF...
   
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