MESOSCALE DISCUSSION 0816
   NWS STORM PREDICTION CENTER NORMAN OK
   0521 PM CDT THU MAY 19 2011
   
   AREAS AFFECTED...WRN OK/NWRN TX
   
   CONCERNING...TORNADO WATCH 308...
   
   VALID 192221Z - 192345Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 308 CONTINUES.
   
   SEVERE/TORNADO THREAT CONTINUES -- MOST IMMEDIATELY WITH A PAIR OF
   SUPERCELLS AFFECTING KIOWA AND NOW SWRN CADDO COUNTIES IN SWRN OK.
   
   LATEST RADAR IMAGERY SHOWS A PAIR OF SUPERCELLS OVER KIOWA COUNTY --
   ONE STRENGTHENING OVER THE CENTRAL PORTION OF THE COUNTY AND A
   SECOND MOVING INTO SWRN CADDO COUNTY.  THE STORM MOVING ACROSS FAR
   SERN KIOWA COUNTY APPEARS TO HAVE SPUN UP A NEW LOW-LEVEL AREA OF
   ROTATION...WHICH WILL IS IN THE PROCESS OF SHIFTING INTO SWRN CADDO
   COUNTY ATTM.
   
   COORDINATION WITH WFO NORMAN HAS RESULTED IN AN ADDITION OF GRADY
   COUNTY INTO WW 308.  WE CONTINUE TO MONITOR THE I-35 CORRIDOR...AND
   POSSIBLE LATER EXTENSION IN AREA INTO CANADIAN/OKLAHOMA/
   MCCLAIN/CLEVELAND COUNTIES.  
   
   MEANWHILE...DEVELOPMENT HAS BEEN MORE SLOW TO INCREASE ACROSS NWRN
   TX...AS A WEAK/SUBTLE WAVE HINTED AT IN WV IMAGERY SHIFTS NNEWD
   TOWARD SWRN OK.  SUPERCELL EVOLUTION INTO TX REMAINS POSSIBLE
   HOWEVER OVER THE NEXT COUPLE OF HOURS AS CU FIELD CONTINUES TO SHOW
   ONGOING MODERATE DEVELOPMENT.
   
   FARTHER NW INTO NWRN OK...BOUNDARY LAYER COOLING/STABILIZATION
   APPEARS TO HAVE OCCURRED PER VISIBLE IMAGERY AND SURFACE
   OBSERVATIONS...IN THE WAKE OF A STORM CLUSTER WHICH HAS MOVED INTO S
   CENTRAL KS.  THUS...IMMEDIATE FOCUS FOR STRONGER STORMS REMAINS OVER
   THE SRN HALF OF THE WW ATTM.
   
   ..GOSS.. 05/19/2011
   
   
   ATTN...WFO...FWD...OUN...SJT...LUB...
   
   LAT...LON   33209902 33060011 35129936 36989884 36879742 36129709
               35019698 34049810 33209902