MESOSCALE DISCUSSION 0729
   NWS STORM PREDICTION CENTER NORMAN OK
   0637 PM CDT SAT MAY 23 2015

   AREAS AFFECTED...SOUTHERN/CENTRAL OK AND NORTH TX

   CONCERNING...TORNADO WATCH 197...

   VALID 232337Z - 240100Z

   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 197 CONTINUES.

   SUMMARY...HEAVY RAINFALL ASIDE...SHORT-TERM TORNADO THREAT WILL
   LIKELY REMAIN MAXIMIZED ACROSS SOUTH-CENTRAL/EAST-CENTRAL OK THROUGH
   EARLY/MID-EVENING. TORNADO WATCH 197 CONTINUES UNTIL 07Z...WHILE
   ADDITIONAL PORTIONS OF EAST-CENTRAL OK MAY REQUIRE AN ADDITIONAL
   TORNADO WATCH.

   DISCUSSION...A COMPOSITE NORTHEAST-SOUTHWEST ORIENTED SQUALL LINE
   CONTINUES TO SLOWLY SPREAD EAST-SOUTHEASTWARD ACROSS
   NORTH-CENTRAL/SOUTHWEST OK AS OF 2330Z/630 PM CDT...WHILE OTHER
   SEMI-DISCRETE STORMS CONTINUE TO QUICKLY DEVELOP/INTENSIFY TO THE
   EAST-SOUTHEAST OF THE SQUALL LINE ACROSS SOUTH-CENTRAL/CENTRAL OK.
   THESE SEMI-DISCRETE STORMS HAVE BEEN VERY QUICK TO ACQUIRE LOW-LEVEL
   ROTATION INCLUDING A HISTORY OF SEVERAL TORNADOES IN AREAS TO THE
   IMMEDIATE WEST/SOUTH OF THE OKC METRO AS OF 630 PM CDT. SCENARIO
   WILL LIKELY REMAIN VERY FAVORABLE FOR AT LEAST TRANSIENT SUPERCELLS
   WITH A TORNADO WITHIN A TROPICAL-LIKE AIR MASS CHARACTERIZED BY
   LOWER 70S F SURFACE DEWPOINTS. LOW-LEVEL WINDS REMAIN BACKED TO
   SOUTHEASTERLY EAST/SOUTHEAST OF THE SQUALL LINE...WHICH IS
   CONTRIBUTING TO STRONG LOW-LEVEL SRH WITH LATEST WSR-88D VWP DATA
   FROM KTLX INDICATING AROUND 350 M2/S2 OF 0-1 KM SRH.

   ..GUYER.. 05/23/2015


   ATTN...WFO...TSA...FWD...OUN...

   LAT...LON   34179951 35129831 35819736 36459609 36489521 34649489
               33169678 33379891 34179951