MESOSCALE DISCUSSION 0003
   NWS STORM PREDICTION CENTER NORMAN OK
   0353 PM CST TUE JAN 08 2013
   
   AREAS AFFECTED...PORTIONS S AND SW TX INVOF RIO GRANDE VALLEY...EWD
   ROUGHLY TO JCT-SAT-MFE LINE.
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 082153Z - 090030Z
   
   PROBABILITY OF WATCH ISSUANCE...40 PERCENT
   
   SUMMARY...THROUGH REMAINDER AFTERNOON INTO EARLY EVENING -- I.E.
   THROUGH 03Z -- CONDITIONS ARE EXPECTED TO BECOME MORE FAVORABLE FOR
   SVR OVER OUTLINED AREA ALONG AND E OF RIO GRANDE VALLEY.  ONSET
   TIMING OF SFC-BASED SVR RISK OVER MAINLY DEEP S TX REMAINS
   UNCERTAIN...BUT WW MAY BE REQUIRED IN NEXT COUPLE OF HOURS.
   
   DISCUSSION...SFC MESOANALYSIS INDICATES LOW INVOF NRN ZAPATA
   COUNTY...WITH WAVY WARM FRONT EWD OVER BROOKS COUNTY...NEWD TO NEAR
   BYY...THEN EWD OVER WATERS OFFSHORE GLS.  QUASISTATIONARY FRONTAL
   ZONE EXTENDS SWWD INTO DEEPER LOW OVER HIGH TERRAIN OF NRN MEX. 
   AREAS OF LOW PRESSURE SHOULD BLEND GRADUALLY AS MID-UPPER LEVEL
   CYCLONE PIVOTS EWD FROM ITS LATEST POSITION ABOUT 250 NM S ELP. 
   CONSIDERABLE PRECIP OVER GULF HAS DIFFUSED TX COASTAL FRONTAL ZONE
   SOMEWHAT...WITH PUREST MARITIME/TROPICAL AIR LOCATED WELL OUT OVER
   OPEN GULF S OF OUTFLOW BOUNDARIES.  STILL...BROAD/STRENGTHENING LLJ
   IS EXPECTED TO CONTRIBUTE TO SHALLOWER AND LESS STABLE BOUNDARY
   LAYER N OF FRONT WITH TIME...WHILE THETAE ADVECTION INCREASES
   BUOYANCY ON BOTH SIDES OF FRONT.  DEEP SHEAR WILL STRENGTHEN WITH
   APCH OF CYCLONE ALOFT...INCREASING ORGANIZED CONVECTIVE/SVR THREAT
   WITH ACTIVITY MOVING NEWD OUT OF CURRENT TSTM GENESIS REGION OVER
   MEX PLATEAU.  STG CAPPING HAS BEEN EVIDENT IN 12Z MONTERREY SOUNDING
   AS WELL AS SEVERAL MODEL FCST SOUNDINGS ACROSS S TX AHEAD OF MEX
   CONVECTION...INDICATING LOW PROBABILITY OF DEVELOPMENT NEAR SFC LOW
   OR FRONT PRIOR TO ARRIVAL OF STRONGER LARGE-SCALE LIFT RELATED TO
   CYCLONE ALOFT. 
   
   DAYLONG PERSISTENCE OF LOW-CLOUD COVER AND RELATED STABILIZING
   EFFECTS SUGGEST SOME DELAY IN SFC-BASED SVR POTENTIAL WITH
   CONVECTION MOVING NEWD OUT OF MEX.  ACTIVITY IS EXPECTED TO STAY
   ELEVATED OVER NRN PORTIONS OF THIS AREA...WITH MAIN CONCERN BEING
   MRGL SVR HAIL AND OCNL STG GUSTS.  HOWEVER...EROSION OF STABLE LAYER
   OVER DEEP S TX...COMBINED WITH INCREASINGLY INTENSE QLCS-MODE
   ORGANIZATION THIS EVENING...SHOULD LEAD TO GRADUAL INCREASE IN WIND
   THREAT WITH TIME.
   
   ..EDWARDS/MEAD.. 01/08/2013
   
   
   ATTN...WFO...CRP...EWX...BRO...SJT...
   
   LAT...LON   29780050 30020013 30459966 30379896 29979870 29329849
               26219853 26239868 26369880 26379909 26499911 26549919
               26839926 26909938 27009938 27029946 27259947 27299954
               27379944 27519949 27629957 27659970 27829988 28140008
               28260028 28510038 29140067 29150079 29240077 29780050