CHICAGO, ILLINOIS — An elevated risk for severe weather stretches from the Midwest to the Great Lakes on Monday, August 10, with Chicago, Detroit, Cleveland and Pittsburgh falling within a 15% severe probability corridor, according to an outlook updated at 12:13 PM ET Friday, August 7. A broad cyclonic corridor will establish moisture and instability from the Plains to the Midwest early next week, with scattered storms expected to fire Monday afternoon and evening from eastern Nebraska to the southern Great Lakes.
Highest Threat Focuses From Northern Illinois to Western Pennsylvania
The 15% severe probability zone, shown in yellow, forms a broad corridor stretching from near Madison and Milwaukee southeast through Chicago, Rockford, Toledo, Fort Wayne, Cleveland and Pittsburgh. Forecasters specifically highlight that the highest severe threat will focus from northern Illinois into western Pennsylvania, where supercells and line segments will be capable of producing damaging wind gusts.
This corridor represents where the combination of the cyclonic pattern’s moisture and instability is expected to be most favorable for organized, potentially long-lived storm structures capable of significant wind impacts.
Supercells and Line Segments Expected Monday Afternoon Into Evening
Forecasters say scattered storms will fire Monday afternoon and evening across the highlighted corridor, with supercells initially developing before organizing into line segments as the event progresses. This evolution from discrete storm cells to a more organized line is typical when a broad cyclonic pattern establishes sufficient moisture and instability over a wide corridor.
Communities including Chicago, Fort Wayne, Toledo, Cleveland and Pittsburgh should be prepared for the potential of damaging wind gusts as these storm structures track through during the Monday afternoon and evening window.
Timing for Monday, August 10
The outlook is valid for Monday, August 10, with the broad cyclonic corridor expected to establish itself across the Plains and Midwest early next week before scattered storms fire during the afternoon and evening hours. Areas farther south, including Indianapolis, Columbus and Cincinnati, sit just outside the highlighted 15% probability zone…