MESOSCALE DISCUSSION 0715
   NWS STORM PREDICTION CENTER NORMAN OK
   0911 PM CDT SUN MAY 19 2013
   
   AREAS AFFECTED...CNTRL IA
   
   CONCERNING...TORNADO WATCH 183...
   
   VALID 200211Z - 200315Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 183 CONTINUES.
   
   SUMMARY...AN ISOLATED SEVERE WEATHER THREAT MAY PERSIST BEYOND THE
   03Z EXPIRATION OF TORNADO WATCH 183.  AS SUCH...A LOCAL EXTENSION IN
   TIME COULD BE REQUIRED.
   
   DISCUSSION...TSTMS HAVE BECOME WIDESPREAD ACROSS S-CNTRL IA WITHIN A
   ZONE OF DCVA ATTENDANT TO A MIDLEVEL VORTICITY MAXIMUM PIVOTING NEWD
   THROUGH THE LOWER-MO VALLEY.  THE AIR MASS AHEAD OF ONGOING STORMS
   REMAINS AT LEAST MODESTLY UNSTABLE...AND GIVEN THE COLOCATION OF A
   700-500-MB WIND MAXIMUM...SUFFICIENT VERTICAL SHEAR EXISTS TO
   SUPPORT ORGANIZED STORM STRUCTURES WITH A CONTINUED RISK FOR SEVERE
   WEATHER.
   
   TO THE WEST OF THE ONGOING STORMS...THE SEVERE WEATHER THREAT HAS
   DIMINISHED AND EXISTING PORTIONS OF WATCH CAN BE CLEARED OR ALLOWED
   TO EXPIRE AT 03Z.
   
   ..MEAD.. 05/20/2013
   
   
   ATTN...WFO...DMX...
   
   LAT...LON   41499332 42119318 42289258 41919230 41329255 40909228
               40649240 40639318 40649369 40779388 41499332