CHICAGO, ILLINOIS — Forecasters are expressing high confidence in a significant severe weather outbreak across a large portion of the Corn Belt from next Monday through Thursday, with the focused corridor of greatest concern covering a broad swath from South Dakota and Nebraska through Minnesota, Iowa, Wisconsin, and into Illinois and Indiana. The upper-air environment combined with favorable thermodynamics and kinematics will support long-lived complexes of thunderstorms capable of producing swaths of damaging to destructive winds.
Major cities including Chicago, Rockford, Aurora, Minneapolis, Omaha, Des Moines, and Milwaukee all fall within the highlighted significant severe weather zone. Some uncertainty remains regarding the exact placement of the heaviest activity on each individual day.
High Confidence Corridor Stretches From South Dakota to Illinois
The focused red zone of significant severe weather extends from Aberdeen and Sioux Falls in South Dakota through Minneapolis, St. Paul, Eau Claire, and Rochester in Minnesota, then sweeps south and east through Iowa City, Cedar Rapids, Davenport, Des Moines, and Sioux City before reaching Rockford, Chicago, and Madison. This corridor represents the highest confidence area for destructive storm impacts.
Destructive Winds Primary Threat From Long Lived Storm Complexes
Favorable upper-air dynamics and supportive thermodynamics and kinematics are expected to fuel long-lived mesoscale convective complexes capable of producing swaths of damaging to destructive straight-line winds across the region. These types of systems can maintain intensity for many hours and cover enormous geographic footprints overnight.
Nebraska Iowa and Wisconsin Also at Risk
Omaha, Lincoln, Norfolk, and Grand Island in Nebraska sit within the severe weather corridor, as do large portions of Wisconsin including Milwaukee, Wausau, and Green Bay. Severe weather is also likely in some areas outside the primary red zone, expanding the overall threat footprint across the broader Midwest.
Exact Day by Day Placement Still Uncertain
While confidence in a significant outbreak from Monday through Thursday is high, the precise location of the heaviest activity on each individual day carries some uncertainty. Forecasters expect to begin breaking down the event day by day in upcoming updates as the pattern comes into better focus.
Stay with NapervilleLocal.com for the latest weather updates and local forecast coverage.…