MESOSCALE DISCUSSION 1681
   NWS STORM PREDICTION CENTER NORMAN OK
   0709 PM CDT THU JUL 21 2011
   
   AREAS AFFECTED...SRN IA...W-CNTRL IL...FAR NRN MO
   
   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 
   
   VALID 220009Z - 220145Z
   
   AN ISOLATED THREAT FOR STRONG STORMS WILL OCCUR THROUGH EARLY
   EVENING. WHILE CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED...THE
   ISOLATED NATURE OF ANY SVR THREAT WILL LIKELY PRECLUDE THE NEED FOR
   A WW.
   
   EARLY EVENING MESOANALYSIS AND VISIBLE SATELLITE IMAGES REVEAL A
   NWD-MOVING WARM FRONT DRAPED ACROSS SRN IA INTO W-CNTRL IL. AREAS OF
   PRECIPITATION ON THE COOL SIDE OF THIS BOUNDARY ACROSS CNTRL IA ARE
   MAINTAINING ITS BAROCLINICITY. SUFFICIENT MOISTURE CONVERGENCE ALONG
   THIS BOUNDARY...AIDED BY DIVERGENT FLOW SOUTH OF A 1012-MB MESOHIGH
   CENTERED OVER N-CNTRL IA...HAS PROMPTED THE INITIATION OF STRONG
   CONVECTION EARLIER OVER MONROE COUNTY IA...WITH ADDITIONAL ATTEMPTS
   AT INITIATION FARTHER WEST INTO LUCAS COUNTY...AND ACROSS LOUISA
   COUNTY IA. DESPITE MODEST MID-LEVEL LAPSE RATES EVIDENT IN THE 00Z
   DAVENPORT IA SOUNDING...THE COMBINATION OF SFC TEMPERATURES IN THE
   LOWER TO MIDDLE 90S AND DEWPOINTS IN THE LOWER/MIDDLE 70S IS
   SUPPORTING MODERATE INSTABILITY NEAR AND SOUTH OF THE WARM FRONT.
   THIS COULD SUPPORT VIGOROUS CONVECTION...AIDED BY 34 KT OF 0-6-KM
   BULK SHEAR EVIDENT IN THE 00Z DAVENPORT SOUNDING. GIVEN THESE
   PARAMETERS...LARGE HAIL AND DMGG WIND GUSTS COULD OCCUR IN
   ASSOCIATION WITH GENERALLY MULTICELLULAR CONVECTION. HOWEVER...THE
   LACK OF MID-LEVEL FORCING FOR ASCENT AND THE ABSENCE OF STRONG
   LOW-LEVEL INFLOW SHOULD LIMIT THE COVERAGE OF ANY SVR THREAT TO
   ISOLATED.
   
   ..COHEN.. 07/22/2011
   
   
   ATTN...WFO...ILX...DVN...DMX...EAX...
   
   LAT...LON   40529045 40319283 40509447 40999485 41419435 41689238
               41559038 40928983 40529045