MESOSCALE DISCUSSION 0729
   NWS STORM PREDICTION CENTER NORMAN OK
   0327 PM CDT MON MAY 20 2013
   
   AREAS AFFECTED...NERN MO...CNTRL IL...W-CNTRL IND
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 202027Z - 202130Z
   
   PROBABILITY OF WATCH ISSUANCE...60 PERCENT
   
   SUMMARY...PROSPECTS FOR TSTM DEVELOPMENT ARE SOMEWHAT UNCERTAIN
   ACROSS W-CNTRL IND WWD INTO NERN MO...BUT THE ENVIRONMENT IS
   FAVORABLE FOR DMGG WINDS AND HAIL GIVEN STRONG
   HEATING/DESTABILIZATION.  CONVECTIVE TRENDS ARE BEING MONITORED FOR
   A POSSIBLE WW...PARTICULARLY ACTIVITY DEVELOPING NEWD FROM SWRN MO
   TOWARDS THE MID-MS VALLEY.
   
   DISCUSSION...RADAR/SATELLITE TRENDS SHOW A DECAYING TSTM CLUSTER/MCV
   MOVING ACROSS N-CNTRL IL...WITH AN INCREASE IN SHALLOW BOUNDARY
   LAYER CU NOTED ACROSS E-CNTRL IL. THIS APPEARS TO BE DEVELOPING
   WITHIN A WEAK CONFLUENCE AXIS WHICH EXTENDS FROM 30 SE MMO TO 20 SSW
   SPI. BOTH MODIFIED 12Z RAOBS AND 12Z NAM FORECAST SOUNDINGS SUGGEST
   MLCAPE VALUES HAVE INCREASED TO 1000-1500 J/KG. WHILE THERE IS STILL
   SOME UNCERTAINTY TO WHAT DEGREE TSTMS WILL INTENSIFY/ORGANIZE OVER
   IL...A THREAT FOR DMGG WINDS AND LARGE HAIL COULD DEVELOP GIVEN
   STEEP LOW-LEVEL LAPSE RATES AND MODERATELY STRONG DEEP-LAYER SHEAR.
   ADDITIONALLY...TSTMS CURRENTLY DEVELOPING OVER WRN MO SHOULD
   EXPAND/DEVELOP NEWD TOWARDS E-CNTRL MO THROUGH LATE AFTERNOON. IT IS
   UNCERTAIN WHETHER A WW WILL BE REQUIRED WITHIN THE NEXT 1-2
   HRS...BUT CONVECTIVE TRENDS CONTINUE TO BE MONITORED.
   
   ..ROGERS/KERR.. 05/20/2013
   
   
   ATTN...WFO...IWX...IND...LOT...ILX...LSX...
   
   LAT...LON   39918754 39488867 39078960 38749051 38819154 39059224
               39719220 40199029 40468932 40988874 41188822 41298728
               41208691 40788656 40298664 39918754