MESOSCALE DISCUSSION 1564
   NWS STORM PREDICTION CENTER NORMAN OK
   1250 AM CDT WED JUL 15 2009
   
   AREAS AFFECTED...SERN IA...WCNTRL IL AND NERN/NCNTRL MO
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 150550Z - 150715Z
   
   EAX VWP SAMPLES A 50 KT WSW LLJ AROUND 1KM...FEEDING THE DVLPG MCS
   OVER SERN IA.  OBJ ANALYSIS SUGGESTS THAT PARCELS FEEDING THE STORMS
   WERE ORIGINATING FROM A RESERVOIR OF CAPE EXCEEDING 3K+ J/KG OVER
   NWRN MO.  COMBINATION OF VERY STRONG INSTABILITY AND PRESENCE OF
   45-50 KTS OF EFFECTIVE SHEAR HAVE BEEN FAVORABLE FOR ISOLD
   SUPERCELLS OVER CNTRL IA WITH VERY LARGE HAIL IN THE DES MOINES
   METRO AREA.
   
   STORM NUMBER IS INCREASING AND MAY BE DETRIMENTAL TO SUSTAINED
   ROTATING UPDRAFTS.  RATHER...BRIEF SUPERCELLS AMIDST A GROWING MCS
   WILL BE PSBL.  THE LLJ IS EXPECTED TO VEER AND AIM INTO THE KSTL
   REGION BY 12Z WITH H85-H7 TEMPERATURES WARMING OVER NWRN MO.  THIS
   WILL LIKELY FOCUS POTENTIAL FOR LARGE HAIL...GUSTY WINDS AND
   BACKBUILDING/TRAINING HEAVY RNFL THREAT INTO NCNTRL/NERN MO AND
   WCNTRL IL THROUGH 09Z OR SO.
   
   ..RACY.. 07/15/2009
   
   
   ATTN...WFO...ILX...LSX...DVN...DMX...EAX...
   
   LAT...LON   41489286 41149098 40639039 40039030 39459049 39349117
               39469198 39749291 40379364 40979363 41489286