MESOSCALE DISCUSSION 1204
   NWS STORM PREDICTION CENTER NORMAN OK
   0652 AM CDT MON JUN 13 2011
   
   AREAS AFFECTED...MO...IL
   
   CONCERNING...SEVERE THUNDERSTORM WATCH 471...
   
   VALID 131152Z - 131315Z
   
   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 471
   CONTINUES.
   
   SEVERAL SPLITTING SUPERCELLS WITH LARGE HAIL HAVE SPREAD ACROSS
   PORTIONS OF CNTRL MO THIS MORNING. THIS DEVELOPMENT HAS OCCURRED AS
   A RESULT OF PERSISTENT LIFT AND MOISTENING WITHIN A LARGER SCALE
   WARM CONVEYOR BELT BETWEEN GREAT LAKES ANTICYCLONE AND SRN HIGH
   PLAINS LEE/THERMAL LOW. DEEP ASCENT WITHIN THIS ZONE HAS LIKELY BEEN
   FURTHER ENHANCED BY THE PASSAGE OF A MID/UPPER LEVEL SPEED MAX
   CROSSING NRN MO THIS MORNING.
   
   GIVEN THE LARGE RESERVOIR OF POTENTIAL INSTABILITY RESIDING WITHIN
   CAPPED AIR MASS UPSTREAM FROM ONGOING DEVELOPMENT...AND CONTINUING
   LIFT ACROSS THE LOW THROUGH MID LEVEL FRONTAL SURFACE...IT APPEARS
   ADDITIONAL STORMS ARE BEGINNING TO DEVELOP NEAR THE SRN EDGE OF WW
   471. SEVERAL COUNTIES ACROSS SWRN MO HAVE BEEN ADDED TO WATCH 471 TO
   ACCOUNT FOR THIS RECENT DEVELOPMENT.
   
   GREATEST THREAT IN THE NEAR TERM ACROSS WW 471 WILL CONTINUE TO BE
   LARGE HAIL. UPSCALE EVOLUTION COINCIDENT WITH DIURNAL HEATING MAY
   RESULT IN AN INCREASE IN THE THREAT FOR DAMAGING WIND GUSTS LATER
   THIS MORNING.
   
   ..CARBIN.. 06/13/2011
   
   
   ATTN...WFO...PAH...ILX...LSX...DVN...SGF...EAX...
   
   LAT...LON   39449425 39479456 40499455 40529235 40269231 40099059
               39559057 39568967 37848960 37649015 37339019 37269067
               37039082 37049100 37409123 37409164 37559188 37779250
               37919307 38169413 39449425