In its day 1 update, the Storm Prediction Center continues to include much of northern Illinois in a slight risk area for severe thunderstorms. Severe thunderstorms are ongoing across northern Iowa, and this activity is expected to continue building into SW Wisconsin. The storm complex may then move east/southeast into northern Illinois later this afternoon, and into the evening hours.
Valid 091630Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE UPPER MISSISSIPPI VALLEY...SOUTH-CENTRAL PLAINS TO MID-SOUTH...AND THE CENTRAL HIGH PLAINS... ...SUMMARY... Severe thunderstorms are possible this afternoon and evening across the Upper Mississippi Valley, south-central Plains and Mid-South, as well as the northern and central High Plains. ...Upper Mississippi Valley/Upper Midwest... A prominent MCV over Iowa will continue to influence strong/severe thunderstorm development this afternoon, particularly near/south of an outflow-reinforced boundary that extends east-northeastward across southeast Minnesota into Wisconsin. Other storms should also develop south-southeastward this afternoon across eastern Iowa into northern Illinois near/east of the cold front. Damaging winds should be the primary concern, but some severe hail is possible, and some tornado threat may exist as well.
Severe storms are already in progress to our west and north:
In addition, satellite imagery shows at least two thunderstorm outflow boundaries over Wisconsin that will likely act as a focus for new storm development through early afternoon. Observation show dew point pooling taking place across eastern Iowa, into northern Illinois, and this air has become quite unstable.