MESOSCALE DISCUSSION 0596
   NWS STORM PREDICTION CENTER NORMAN OK
   0536 AM CDT MON APR 27 2009
   
   AREAS AFFECTED...THE ERN PERMIAN BASIN EWD INTO CNTRL TX
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 197...
   
   VALID 271036Z - 271200Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 197
   CONTINUES.
   
   THE THREAT FOR HAIL...DAMAGING WIND GUSTS AND EXCESSIVE RAINFALL
   CONTINUES ACROSS CNTRL/SRN PORTIONS OF WW AREA.  THIS THREAT MAY
   BEGIN TO DEVELOP E OF WW 197 OVER THE NEXT COUPLE OF HOURS AND
   CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE WW.
   
   UPSCALE GROWTH OF ELEVATED TSTMS INTO AN MCS HAS OCCURRED OVER THE
   PAST 2-3 HOURS WITH THE LEADING EDGE OF SYSTEM COLD POOL EXTENDING
   FROM REAGAN AND IRION COUNTIES EWD TO SRN MCCULLOCH AND SAN SABA
   COUNTIES AS OF 1023Z.  FARTHER E...TSTMS HAVE RECENTLY DEVELOPED
   OVER MILLS AND HAMILTON COUNTIES NEWD INTO BOSQUE...SOMERVELL AND
   HOOD COUNTIES WITHIN A ZONE OF ENHANCE WAA...IMMEDIATELY DOWNSTREAM
   FROM EVOLVING MCS.
   
   FORCING FOR ASCENT ASSOCIATED WITH MIDLEVEL IMPULSE CURRENTLY
   TRANSLATING ENEWD THROUGH THE BIG BEND REGION...COUPLED WITH
   ENHANCED SYSTEM-RELATIVE INFLOW ALONG 30-40 KT SLY LLJ SHOULD
   MAINTAIN MCS SEWD THIS MORNING WITH A CONTINUED THREAT OF DAMAGING
   WINDS AND SOME HAIL.  ECHO TRAINING/BACKBUILDING STORM DEVELOPMENT
   WILL ALSO RESULT IN LOCALLY EXCESSIVE RAINFALL WITH HOURLY RATES
   APPROACHING 2 INCHES.
   
   AS MENTIONED ABOVE...ADDITIONAL TSTMS HAVE FORMED ALONG ERN FRINGE
   OF MCS /E OF WW 197/ WITHIN PRIMARY CORE OF 45-55 KT SLY LLJ WHERE
   LOWER TROPOSPHERIC WAA IS BEING ENHANCED.  THIS ACTIVITY MAY
   CONTINUE TO INTENSIFY THROUGH THE MORNING AS UPSTREAM IMPULSE
   APPROACHES THE REGION.  GIVEN THE INFLUX OF A MOIST/MODERATELY
   UNSTABLE AIR MASS AND SUFFICIENT VERTICAL SHEAR FOR STORM
   ORGANIZATION...ASSOCIATED SEVERE THREAT MAY INCREASE THROUGH 12Z.
   
   ..MEAD.. 04/27/2009
   
   
   ATTN...WFO...FWD...EWX...SJT...MAF...
   
   LAT...LON   30550126 30740169 31380182 31830164 32060091 31889958
               31879890 32169802 32159747 31669730 30819821 30289971
               30550126