MESOSCALE DISCUSSION 1237, AREAS AFFECTED...SE MI...NE/CNTRL IND...FAR NW OH CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

        MESOSCALE DISCUSSION 1237     NWS STORM PREDICTION CENTER NORMAN OK     0231 PM CDT THU JUN 21 2012          AREAS AFFECTED...SE MI...NE/CNTRL IND...FAR NW OH          CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY           VALID 211931Z - 212030Z          PROBABILITY OF WATCH ISSUANCE...20 PERCENT          SUMMARY...ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED THIS     AFTERNOON ACROSS PORTIONS OF SE MI...NE/CNTRL IND AND FAR NW OH. A     FEW OF THESE STORMS MAY BE BRIEFLY SEVERE WITH THE PRIMARY THREATS     OF STRONG WINDS AND HAIL. ISOLATED/BRIEF NATURE OF THE SEVERE THREAT     IS EXPECTED TO PRECLUDE THE NEED FOR A WW.          DISCUSSION...ISOLATED THUNDERSTORMS ARE BEGINNING TO DEVELOP ALONG A     FRONTAL BOUNDARY MOVING EWD ACROSS THE UPPER GREAT LAKES/WRN OHIO     VALLEY. 18Z SURFACE ANALYSIS DEPICTED THE FRONT ALONG A LINE FROM     BAX SWWD TO LAF. THE ENVIRONMENT AHEAD OF THE FRONT IS CHARACTERIZED     BY TEMPERATURES IN THE UPPER 80S TO LOW 90S AND DEWPOINTS AROUND 60.     THIS WARM...MODERATELY MOIST ENVIRONMENT WILL CONTINUE TO PROMOTE     MLCAPE VALUES NEAR 500-1000 J/KG. THIS MODEST INSTABILITY COMBINED     WITH EFFECTIVE SHEAR VALUES AROUND 20 TO 30 KTS WILL SUPPORT BRIEF     STORM ORGANIZATION AND A FEW STORMS CAPABLE OF PRODUCING SEVERE     WIND/HAIL. ONE FACTOR WORKING AGAINST SEVERE STORM DEVELOPMENT IS     THE WARM TEMPERATURES ALOFT /AROUND 8 DEG C AT 700 MB BASED ON THE     LATEST MESOANALYSIS/ WHICH ARE EXPECTED TO KEEP CAPE PROFILES THIN     AND LIMIT THE OVERALL COVERAGE OF THUNDERSTORMS. ISOLATED/BRIEF     NATURE OF THE SEVERE THREAT IS EXPECTED TO PRECLUDE THE NEED FOR A     WW.          ..MOSIER/HART.. 06/21/2012               ATTN...WFO...CLE...ILN...DTX...IWX...GRR...IND...ILX...          LAT...LON   41958517 42208494 42888425 42958355 42508303 41518372                 40438483 39348630 39468786 40428663 41958517