MESOSCALE DISCUSSION 2203
   NWS STORM PREDICTION CENTER NORMAN OK
   0901 PM CDT SUN SEP 25 2011
   
   AREAS AFFECTED...PARTS OF SRN AR...W CNTRL  MS
   
   CONCERNING...TORNADO WATCH 855...
   
   VALID 260201Z - 260330Z
   
   THE SEVERE WEATHER THREAT FOR TORNADO WATCH 855 CONTINUES.
   
   AN ADDITIONAL WW IS NOT ANTICIPATED...BUT IT IS POSSIBLE THAT
   PORTIONS OF THE WW MAY BE EXTENDED LOCALLY IN TIME BY ANOTHER HOUR
   OR TWO.
   
   VIGOROUS STORM DEVELOPMENT CONTINUES ALONG AND JUST AHEAD OF A
   SOUTHEASTWARD ADVANCING COLD FRONT ACROSS NORTHWEST MISSISSIPPI AND
   SOUTHERN ARKANSAS.  HOWEVER...STRONGER MID/UPPER FORCING FOR UPWARD
   VERTICAL MOTION ASSOCIATED WITH A SHORT WAVE IMPULSE PIVOTING AROUND
   THE MIDDLE MISSISSIPPI VALLEY CLOSED LOW CONTINUES GRADUALLY
   SHIFTING AWAY FROM THE REGION...ACROSS AND NORTH OF THE LOWER OHIO
   VALLEY.  AND THE PRE-FRONTAL BOUNDARY LAYER CONTINUES TO SLOWLY
   STABILIZE WITH THE LOSS OF DAYTIME HEATING.  RECENT OBSERVATIONAL
   DATA ALREADY SUGGEST GENERAL WEAKENING TRENDS TO CONVECTION MAY BE
   UNDERWAY...AND STORM WEAKENING/DISSIPATION SEEMS LIKELY TO PROGRESS
   DURING THE NEXT FEW HOURS.
   
   ..KERR.. 09/26/2011
   
   
   ATTN...WFO...MEG...JAN...LZK...SHV...
   
   LAT...LON   33199288 33589167 33839033 34058984 33438909 32738917
               32699056 32909233 33199288