MESOSCALE DISCUSSION 1775
   NWS STORM PREDICTION CENTER NORMAN OK
   0540 PM CDT THU JUL 28 2011
   
   AREAS AFFECTED...SOUTHERN IA/NORTHERN MO INTO NORTHERN IL
   
   CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 
   
   VALID 282240Z - 290015Z
   
   STRONG/SEVERE TSTMS MAY INCREASE THROUGH EARLY EVENING WITHIN A
   CORRIDOR ACROSS SOUTHERN IA/FAR NORTHERN MO INTO NORTHERN IL.
   DAMAGING WINDS/PERHAPS SEVERE HAIL AND LOCALLY HEAVY RAINFALL WILL
   BE POSSIBLE. THE NEED FOR A WATCH IS UNCERTAIN...BUT
   OBSERVATIONAL/CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED.
   
   A FEW STORMS HAVE RECENTLY DEVELOPED ACROSS SOUTH-CENTRAL/SOUTHEAST
   IA...GENERALLY JUST WEST OF THE OTTUMWA/CENTERVILLE IA AREAS AS OF
   2230Z. THESE STORMS ARE DEVELOPING IN VICINITY OF A WEAK SURFACE LOW
   AND A DIFFERENTIAL HEATING/SYNOPTIC FRONTAL BOUNDARY THAT ANGLES
   SOUTHWEST-NORTHEAST ACROSS THE REGION. ALONG THE SOUTHERN EDGE OF
   THIS BOUNDARY/ASSOCIATED THICKER CLOUD COVER...THE BOUNDARY LAYER IS
   STRONGLY UNSTABLE /MLCAPE 3000-4500 J PER KG/ AMID MIDDLE 70S F
   SURFACE DEWPOINTS. WHILE THE AIRMASS IS VERY UNSTABLE...LACK OF
   DISCERNIBLE LARGE SCALE FORCING FOR ASCENT AND WARM THERMAL PROFILES
   ALOFT PUTS THE DEGREE/EXTENT OF VIGOROUS TSTM DEVELOPMENT INTO
   QUESTION. THAT SAID...THE DEGREE OF INSTABILITY COMBINED WITH THE
   SOUTHERN EDGE OF STRONGER WESTERLIES ALOFT /40+ KT MID AND HIGH
   LEVEL FLOW AS PER DES MOINES AND DAVENPORT WSR-88D VWPS/ WOULD
   SUPPORT FEW SUPERCELLS/SUSTAINED MULTICELLS CAPABLE OF WIND
   DAMAGE/SOME HAIL AS WELL AS LOCALLY HEAVY RAINFALL.
   
   ..GUYER.. 07/28/2011
   
   
   ATTN...WFO...LOT...ILX...LSX...DVN...DMX...EAX...
   
   LAT...LON   40259434 41039377 42079009 41608876 40688953 39919306
               40259434