MESOSCALE DISCUSSION 0527
   NWS STORM PREDICTION CENTER NORMAN OK
   0349 PM CDT SUN APR 19 2009
   
   AREAS AFFECTED...ERN AR...SERN MO...NRN MS...WRN TN
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 171...172...
   
   VALID 192049Z - 192145Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   171...172...CONTINUES.
   
   FAST MOVING STORMS OCCASIONALLY TAKING ON SUPERCELLULAR
   CHARACTERISTICS WILL CONTINUE TO MOVE ENE THROUGH NRN MS DURING THE
   NEXT HOUR...AND THEN MOVE OUT OF WW 172 AND INTO HUN/OHX CWA/S BY
   22-23Z. THESE STORMS ARE ENTERING AN ENVIRONMENT THAT IS RAPIDLY
   RECOVERING BEHIND EARLIER CONVECTION...WITH CLEARING SKIES ALLOWING
   TEMPERATURES TO WARM INTO THE LOW 70S...AND SURFACE DEWPOINTS
   INCREASING INTO THE MID 60S. RUC SOUNDINGS INDICATE SEVERAL MID LVL
   WARM LAYERS OVER MS...WHICH MAY HINDER MORE ROBUST UPDRAFTS.
   HOWEVER...THIS MAY BE OFFSET BY STRONG UPR FLOW SPREADING OVER
   RELATIVELY BACKED LOW LVL WINDS...YIELDING EFFECTIVE BULK SHEAR
   VALUES AROUND 50-60 KT. THIS FLOW REGIME WILL CONTINUE TO SUPPORT A
   THREAT OF LARGE HAIL...DAMAGING WINDS...AND AN ISOLATED TORNADO.
   
   FARTHER W...A FAST MOVING LINE SEGMENT WAS CROSSING THE MS RIVER
   INTO NWRN MS...WHILE OTHER MULTICELL CLUSTERS/LINE SEGMENTS WERE
   TRAVERSING NERN AR AND SERN MO...WITH ADDITIONAL ACTIVITY SPREADING
   INTO SRN IL WHERE SUNSHINE HAS AIDED IN DESTABILIZATION. REMAINING
   STORMS NOW OCCURRING WITHIN WW 171 HAVE BEEN SLOW TO INTENSIFY...BUT
   SOME POTENTIAL FOR LARGE HAIL REMAINS BEFORE BOUNDARY LAYER
   STABILIZES WITH LOSS OF DAYTIME HEATING.
   
   ..GARNER.. 04/19/2009
   
   
   ATTN...WFO...OHX...PAH...MEG...JAN...LSX...LZK...SGF...
   
   LAT...LON   33778877 33789085 34469062 36469156 37389117 37418915
               36578956 36558760 33778877