MESOSCALE DISCUSSION 0858
   NWS STORM PREDICTION CENTER NORMAN OK
   0300 PM CDT WED MAY 29 2013

   AREAS AFFECTED...SW/S-CNTRL KS...WRN OK AND TX PANHANDLES...WRN OK

   CONCERNING...TORNADO WATCH 239...

   VALID 292000Z - 292100Z

   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 239 CONTINUES.

   SUMMARY...TSTM COVERAGE WILL CONTINUE TO INCREASE THROUGHOUT THE
   AFTERNOON. PRIMARY SVR THREAT REMAINS LARGE HAIL AND STRONG WINDS
   BUT A FEW TORNADOES REMAIN POSSIBLE.

   DISCUSSION...18Z DDC SOUNDING DEPICTED A VOLATILE AIRMASS WITH
   700-500 MB LAPSE RATE OF 9.1 DEG C/KM AND SBCAPE GREATER THAN 3500 J
   PER KG. STEEP MID-LEVEL LAPSE RATES WERE PRESENT ON 18Z AMA AND OUN
   RAOBS AS WELL. THUS FAR...TSTM ACTIVITY HAS STRUGGLED WITH RECENT
   ACTIVITY ALONG THE DRYLINE E OF AMA WEAKENING OVER THE PAST HALF
   HOUR. HOWEVER...THE DRYLINE IS EXPECTED TO CONTINUE PROGRESSING EWD
   INTO A MORE UNSTABLE ENVIRONMENT...FAVORING INCREASE TSTM COVERAGE.

   SHEAR PROFILES ON THE 18Z REGIONAL SOUNDINGS CONTINUE TO INDICATE A
   VEER-BACK-VEER PATTERN...LENDING UNCERTAINTY TO THE MAGNITUDE OF
   ORGANIZATION THE STORMS WILL ACHIEVE. THE SOUNDINGS AT OUN AND FWD
   ALSO SHOW SOME WEAKNESS IN THE FLOW AROUND 500 MB...CURRENTLY
   LIMITING BULK SHEAR VALUES. THE 18Z AMA SOUNDING SHOWED 50 KT AT 500
   MB. AS SUCH...AN INCREASE IN THE FLOW IS EXPECTED FARTHER
   E...SUPPORTING INCREASE STORM ORGANIZATION. 

   OVERALL...THE SVR THREAT IS EXPECTED TO CONTINUE WITH SOME INCREASE
   IN COVERAGE. PRIMARY THREATS ARE HAIL AND WINDS BUT GIVEN THE BACKED
   LOW-LEVEL FLOW...INCREASING DEEP LAYER SHEAR...AND MOIST BOUNDARY
   LAYER...TORNADOES REMAIN POSSIBLE.

   ..MEAD.. 05/29/2013


   ATTN...WFO...ICT...OUN...DDC...GLD...LUB...AMA...

   LAT...LON   36960201 37640200 38530192 39110119 39170021 38859801
               36119770 34369858 33880027 34620139 36960201