MESOSCALE DISCUSSION 0600
   NWS STORM PREDICTION CENTER NORMAN OK
   0806 PM CDT SUN MAY 10 2015

   AREAS AFFECTED...E-CNTRL TX TO SERN OK

   CONCERNING...TORNADO WATCH 155...157...

   VALID 110106Z - 110200Z

   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 155...157...CONTINUES.

   SUMMARY...WITH WW/S 155/157 SCHEDULED TO EXPIRE AT 02Z...SPC IS
   COORDINATING WITH REMAINING WFO/S ON A PROBABLE TEMPORAL EXTENSION
   OVER PARTS OF E-CNTRL TX AND SERN OK.

   DISCUSSION...MAIN SEVERE RISK HAS BECOME BIMODAL WITH AN EMERGING
   SUPERCELL CLUSTER BETWEEN THE METROPLEX AND WACO...AND A SUPERCELL
   CLUSTER OVER SERN OK JUST SW OF FORT SMITH. THE SRN CLUSTER WILL BE
   SUPPORTED BY A COMPARATIVELY GREATER INSTABILITY FEED PER 21Z KCLL
   AND 00Z CRP RAOBS...WHILE THE NRN CLUSTER WILL REMAIN IN THE MIDST
   OF STRONG LOW-LEVEL SHEAR PER KSRX VWP DATA. BOTH CLUSTERS WILL HAVE
   A CONTINUED RISK FOR A TORNADO INTO LATE EVENING. BUT THE
   PREDOMINANT THREAT APPEARS TO BE IN TRANSITION TO DAMAGING WINDS AND
   ISOLATED SEVERE HAIL BASED ON INCREASING CLUSTER/LINEAR MODE.

   ..GRAMS.. 05/11/2015


   ATTN...WFO...LZK...SHV...TSA...FWD...OUN...

   LAT...LON   35399481 35459421 35259408 34819419 34189537 33079600
               32669573 31959539 31629573 31289706 31239745 31609759
               32099695 32559657 33439621 33989643 34329619 35399481