MESOSCALE DISCUSSION 1769
   NWS STORM PREDICTION CENTER NORMAN OK
   0711 AM CDT TUE AUG 04 2009
   
   AREAS AFFECTED...NERN MO...SERN IA...WRN IL
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 654...
   
   VALID 041211Z - 041345Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 654
   CONTINUES.
   
   PRIMARY SEVERE WEATHER THREAT IS EXPECTED ACROSS ERN PORTIONS OF WW
   654 FROM SERN IA THROUGH WRN IL THROUGH 14Z. STORMS HAVE APPROACHED
   THE ERN EDGE OF WW AND ANOTHER WW IS BEING CONSIDERED FARTHER EAST
   INTO CNTRL IL.
   
   A CONVECTIVE OUTFLOW BOUNDARY EXTENDS FROM SERN IA...EXTREME WRN IL
   THEN SWWD AND WWD THROUGH NRN MO. STORMS HAVE STRUGGLED TO DEVELOP
   ALONG SRN FLANKS OF THE OUTFLOW BOUNDARY...MOST LIKELY DUE TO A MORE
   STRONGLY CAPPED ENVIRONMENT OVER CNTRL MO. HOWEVER...RECENT RADAR
   TRENDS HAVE INDICATED STORMS HAVE BEGUN TO FORWARD PROPAGATE ALONG
   PORTION OF OUTFLOW BOUNDARY FROM SERN IA THROUGH WRN IL. POTENTIAL
   EXISTS FOR STORMS TO DEVELOPING EWD THROUGH CNTRL IL THIS MORNING
   ALONG INSTABILITY GRADIENT WHERE THE 12Z LINCOLN RAOB INDICATES A
   WEAK CAP...STRONG INSTABILITY AND STEEP LAPSE RATES IN THE 850-500
   MB LAYER. THE STORMS ARE EMBEDDED WITHIN UNIDIRECTIONAL 30-35 KT
   BULK SHEAR. DAMAGING WIND AND LARGE HAIL WILL REMAIN THE PRIMARY
   THREATS.
   
   ..DIAL.. 08/04/2009
   
   
   ATTN...WFO...ILX...LSX...DVN...DMX...
   
   LAT...LON   40239137 40869275 41279277 41309140 40628995 39179024
               39109121 40239137