MESOSCALE DISCUSSION 0526
   NWS STORM PREDICTION CENTER NORMAN OK
   0222 PM CDT SUN APR 19 2009
   
   AREAS AFFECTED...ERN AR...SERN MO...NRN MS...WRN TN
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 171...172...
   
   VALID 191922Z - 192015Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
   171...172...CONTINUES.
   
   REGIONAL RADAR REFLECTIVITY SHOWS THUNDERSTORM COVERAGE INCREASING
   ACROSS WW 171...AND SPREADING INTO THE SRN PORTION OF WW 172. A
   BOWING LINE SEGMENT MOVING E AT 30-35 WILL MOVE FROM ARKANSAS COUNTY
   AR TOWARD THE MS RIVER DURING THE NEXT HOUR...WHILE A MULTICELL
   CLUSTER CURRENTLY OVER INDEPENDENCE COUNTY AR MOVES E AT 25-30 KT
   TOWARD JACKSON/CRAIGHEAD/POINSETT COUNTIES IN NERN AR. THE BOUNDARY
   LAYER CONTINUES TO DESTABILIZE ACROSS THE REGION GIVEN CLEARING
   SKIES AND APPROACHING UPR COLD POOL OVER NRN AR...WITH MODIFIED RUC
   SOUNDINGS FOR TEMPERATURES IN THE UPR 60S/LOW 70S AND DEWPOINTS IN
   UPR 50S/AROUND 60 YIELDING MLCAPE VALUES OF 500-1000 J/KG. THIS
   ENVIRONMENT WILL CONTINUE TO FAVOR LARGE HAIL WITH THE STRONGER
   UPDRAFT CORES.
   
   A BROKEN LINE OF QUASI DISCRETE THUNDERSTORMS HAS DEVELOPED ALONG
   THE AR/MS BORDER...AND IS MOVING ENE AT AROUND 40 KT. AS THESE
   STORMS MOVE DEEPER INTO WW 172...THEY WILL BEGIN TO ENCOUNTER A
   SHEAR PROFILE SLIGHTLY MORE FAVORABLE FOR SUPERCELL STORM
   STRUCTURES...CHARACTERIZED BY EFFECTIVE BULK SHEAR OF 50 KT AND SRH
   AROUND 100-150 M2/S2. THE THREAT FOR LARGE HAIL AND DAMAGING WINDS
   WILL SUBSEQUENTLY INCREASE...ALONG WITH THE POSSIBILITY FOR AN
   ISOLATED TORNADO.
   
   ..GARNER.. 04/19/2009
   
   
   ATTN...WFO...OHX...PAH...MEG...JAN...LSX...LZK...SGF...
   
   LAT...LON   33429291 35769191 37439116 37418915 36598954 36548762
               33768877 33779089 33449102 33429291