MESOSCALE DISCUSSION 0608
   NWS STORM PREDICTION CENTER NORMAN OK
   0853 PM CDT TUE APR 26 2011
   
   AREAS AFFECTED...PORTIONS E TX...NRN LA...CENTRAL/SRN AR...EXTREME
   SERN OK.
   
   CONCERNING...TORNADO WATCH 215...220...
   
   VALID 270153Z - 270330Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 215...220...CONTINUES.
   
   WWS WILL NEED TO BE REPLACED BEFORE THEIR SCHEDULED 03Z EXPIRATION
   TIME...BECAUSE THREAT FOR TORNADIC SUPERCELLS WILL CONTINUE ACROSS
   MUCH OF THIS REGION WELL INTO OVERNIGHT HOURS E OF COLD
   FRONT/DRYLINE.  FAVORABLE BUOYANCY AND STRENGTHENING OF BOTH
   BOUNDARY-LAYER AND DEEP-TROPOSPHERIC SHEAR ARE EXPECTED.
   
   PRIMARY CONVECTIVE DEVELOPMENT REGION REMAINS NEAR COLD
   FRONT/DRYLINE TRIPLE POINT THAT IS PROPAGATING SWD FROM N-CENTRAL TX
   INTO CENTRAL TX.  CONVECTION WILL CONTINUE TO MOVE EWD ACROSS
   CORRIDOR FROM THERE OVER NE TX AND NRN LA...AND OTHER DEVELOPMENT
   ALSO REMAINS POSSIBLE ALONG FRONTAL ZONE NEWD OVER NE TX AND SWRN
   AR.  ENVIRONMENT IN CONVECTIVELY UNPERTURBED INFLOW AIR WILL BE
   QUITE FAVORABLE...WITH SFC DEW POINTS 70S F HELPING TO MAINTAIN
   SFC-BASED EFFECTIVE INFLOW PARCELS AND MLCAPE 1500-2500 J/KG THROUGH
   AT LEAST 06Z.  LLJ IS EXPECTED TO INTENSIFY TO 60-70 KT ACROSS MUCH
   OF THIS REGION AND VEER ONLY SLIGHTLY AS UPPER TROUGH OVER OK MOVES
   EWD.  THIS WILL ENLARGE LOW-LEVEL HODOGRAPHS CONSIDERABLY WITH 0-1
   KM SRH EXCEEDING 500 J/KG FROM E TX NWD AND EWD.  CAPPING INCREASES
   WITH SWD EXTENT OVER WW 220...MAKING ADDITIONAL DEVELOPMENT MORE
   CONDITIONAL...BUT SVR POTENTIAL WITH ANY SUSTAINED CONVECTION
   REMAINS STG OVER THAT AREA.  CONVECTION THAT HAS BEEN STRUGGLING TO
   INTENSIFY BETWEEN AUS-SAT IS MOVING ESEWD INTO ENVIRONMENT
   CHARACTERIZED BY FAVORABLE MOISTURE AND INCREASING LOW-LEVEL
   SHEAR...BUT ALSO STG CINH.  WHETHER OR NOT THIS ACTIVITY TAKES
   ROOT...SLOW SWD BUILDING OF CENTRAL/E TX COMPLEX ALSO MAY AFFECT
   SOME AREAS NOW COVERED BY WW 220.
   
   ..EDWARDS.. 04/27/2011
   
   
   ATTN...WFO...JAN...LZK...LCH...SHV...TSA...HGX...FWD...EWX...
   
   LAT...LON   29709576 29689712 30049765 31129775 31859716 33099635
               34189497 34569348 34529240 32679202 30949258 29709576