MESOSCALE DISCUSSION 1227
   NWS STORM PREDICTION CENTER NORMAN OK
   0155 AM CDT WED JUN 15 2011
   
   AREAS AFFECTED...IA...MO...IL
   
   CONCERNING...HEAVY RAINFALL 
   
   VALID 150655Z - 151000Z
   
   FOR THE SECOND NIGHT IN A ROW AN EXTREME CONVECTIVE RAINFALL EVENT
   IS UNDERWAY ACROSS SERN IA...NERN MO...AND WRN IL. RAINFALL RATES
   WITHIN THIS SYSTEM ARE LIKELY TO BE OVER 1 INCH PER HOUR AT TIMES
   WITH SOME LOCATIONS PROBABLY EXPERIENCING OCCASIONAL 2 INCH PER HOUR
   RAINFALL RATES.
   
   EVOLVING MCS ACROSS THE REGION APPEARS TO BE UNDERGOING EVEN GREATER
   ORGANIZATION IN ASSOCIATION WITH DEVELOPING SURFACE CYCLONE ANALYZED
   OVER ERN IA AT 0600 UTC. THIS PROCESS WILL ALSO ACT TO ENHANCE MASS
   AND MOISTURE FLUXES WITHIN THE SATURATED AIR MASS TO FURTHER SUPPORT
   LOCALLY EXTREME CONVECTIVE RAINFALL RATES. WHILE COLD POOL HAS
   BECOME WELL DEFINED ACROSS ERN IA AND MAY BEGIN TO PROMOTE FORWARD
   PROPAGATION AND PERHAPS SOME CONVECTIVE WIND THREAT ALONG THE
   LEADING EDGE OF DEEP CONVECTION FROM MS RIVER EAST AND SOUTHEAST
   ACROSS IL...GREATER DANGER WILL REMAIN HEAVY RAIN AND REPEAT STORM
   DEVELOPMENT ALONG THE SRN/SWRN FLANK OF THE MCS...FROM SERN IA AND
   EXTREME NERN MO INTO WRN IL. IT IS IN THESE AREAS WHERE 30-40KT LOW
   LEVEL JET IS DIRECTED ACROSS THE WARM FRONT AND WILL FOSTER
   BACKBUILDING MESO-BETA STORM ELEMENTS FOR AT LEAST A FEW MORE HOURS
   UNTIL STRONGER MID LEVEL FLOW ASSOCIATED WITH THE UPPER TROUGH AIDS
   TO TRANSLATE THE ENTIRE SYSTEM FARTHER EAST.
   
   WE WILL ALSO CONTINUE TO MONITOR THE CHANCE THAT SYSTEM BEGINS TO
   ACCELERATE SEWD ALONG INSTABILITY GRADIENT ALIGNED WITH THE MS
   RIVER. THERE IS SOME PROBABILITY THAT EXPANDING COLD POOL AND
   STRENGTHENING LARGE SCALE FORCING AND FLOW MAY SUPPORT AN EVOLVING
   WIND DAMAGE THREAT ACROSS PARTS OF IL LATER THIS MORNING.
   
   ..CARBIN.. 06/15/2011
   
   
   ATTN...WFO...ILX...LSX...DVN...DMX...EAX...
   
   LAT...LON   39399197 40249305 40749296 41189304 41309282 41039033
               40528871 39678875 38818996 39399197