The Storm Prediction Center in Norman, Oklahoma is monitoring conditions across northern Illinois for possible severe thunderstorm development as a cold front approaches from Iowa. The peg the probability of the issuance of a watch at 40 percent.
AREAS AFFECTED...NRN IL...SRN WI CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 052102Z - 052230Z PROBABILITY OF WATCH ISSUANCE...40 PERCENT SUMMARY...A CONDITIONAL THREAT OF SUPERCELLS WITH LARGE HAIL AND DAMAGING WINDS EXISTS ACROSS FAR NRN IL AND SRN WI...AND THE AREA IS BEING MONITORED FOR POSSIBLE DEVELOPMENT. DISCUSSION...THE AIR MASS ACROSS THE REGION WAS AFFECTED BY EARLY DAY CONVECTION...BUT SOME RECOVERY HAS TAKEN PLACE. STREAMLINES ARE CONVERGING OVER THE AREA BUT SOME CAPPING EXISTS. THE SURFACE THETA-E AXIS REMAINS W OF THE AREA...BUT MORE BUOYANT AIR MAY EVENTUALLY MOVE IN SLOWLY FROM THE SW. IT IS UNCLEAR IF THE FORCING WILL OVERCOME CAPPING...BUT IF IT DOES...CONDITIONS WILL BE QUITE FAVORABLE FOR HAIL AND WIND.
