MESOSCALE DISCUSSION 0938

        MESOSCALE DISCUSSION 0938     NWS STORM PREDICTION CENTER NORMAN OK     1200 PM CDT MON MAY 28 2012          AREAS AFFECTED...IA..WI...IL          CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY           VALID 281700Z - 281800Z          PROBABILITY OF WATCH ISSUANCE...80 PERCENT          SUMMARY...STRONG TO SEVERE TSTMS ARE EXPECTED TO DEVELOP AHEAD OF A     COLD FRONT MOVING INTO AREAS OF EXTREME ERN IA...MUCH OF WI...AND     NRN IL THROUGH THE AFTERNOON. A WATCH IS POSSIBLE ACROSS SOME OR     MOST OF THESE AREAS WITHIN THE NEXT HOUR OR TWO.          DISCUSSION...STRONG ASCENT ACCOMPANYING THE SHORT WAVE TROUGH MOVING     INTO ERN MN AND IA WILL LIKELY AID CONVECTIVE DEVELOPMENT ALONG AND     AHEAD OF A COLD FRONT CURRENTLY SITUATED FROM WRN WI SWWD INTO NERN     IA. AIRMASS AHEAD OF THE FRONT CONTINUES TO DESTABILIZE WITH HEATING     OF THE DAY AND SURFACE-BASED CAPE IS CURRENTLY NEARING 1000 J/KG IN     SOME LOCATIONS. A WIDE ARRAY OF MODEL GUIDANCE INDICATES A     REMARKABLY CONSISTENT SIGNAL FOR THE DEVELOPMENT AND INCREASING     COVERAGE OF DEEP CONVECTION...ESPECIALLY ACROSS NRN AND ERN     WI...THROUGH THIS AFTERNOON. THIS MODEL SIGNAL IS LIKELY A RESULT OF     FAVORABLE LARGE SCALE FORCING FOR ASCENT MOVING INTO THE REGION AND     A LACK OF STRONGER INHIBITION THAN WHAT HAS BEEN IN PLACE IN RECENT     DAYS.          AMBIENT DEEP-LAYER SHEAR OF 40KT WITHIN THE SERN FLANK OF THE LARGE     UPPER LOW TO THE WEST WILL SUPPORT INCREASING STORM ORGANIZATION     WITH SUPERCELLS AND BOWING LINE SEGMENTS POTENTIALLY EVOLVING WITH     TIME. LARGE HAIL AND LOCALLY DAMAGING WINDS MAY ACCOMPANY THE     STRONGER STORMS LATER TODAY.          ..CARBIN.. 05/28/2012