ILLINOIS AND IOWA — The axis of heaviest rain is lining up along I-80 tonight, stretching from the Quad Cities through LaSalle and into Chicago. A pocket of 3 to 6 inches of rainfall is possible within this corridor, raising significant concern for flash flooding as storms are expected to really ramp up after 12 AM. Residents along this stretch are being urged to avoid flooded roads and stay home tonight if possible.
Corridor From Quad Cities to Chicago Faces Heaviest Totals
The highlighted rain axis stretches in a narrow band along I-80, beginning near the Quad Cities and extending eastward through LaSalle, Peru, Ottawa, and continuing toward the Chicago metro area. This corridor represents the zone where forecasters expect the most concentrated and heaviest rainfall totals tonight.
Radar imagery already shows intense rainfall cores, shown in red and orange, tracking through Iowa City, Montezuma, and Wellman, illustrating the kind of heavy rain rates already developing within this corridor even before the overnight ramp-up begins.
Localized Totals Could Reach 3 to 6 Inches Overnight
Forecasters are warning that a localized pocket within this corridor could see rainfall totals reaching 3 to 6 inches, a substantial amount capable of quickly overwhelming drainage systems and leading to significant flash flooding concerns across the affected communities along the I-80 corridor tonight.
This kind of concentrated, heavy rainfall total is exactly the scenario that raises the greatest flooding risk, particularly when it falls within a relatively narrow band rather than spreading out more evenly across a broader area of the region.
Storms Expected to Significantly Intensify After Midnight
While rain and storm activity is already occurring across the region, forecasters specifically note that storms will really ramp up after 12 AM, suggesting the most intense and potentially dangerous phase of tonight’s rain event is still ahead for communities along the highlighted corridor…