CHICAGO – Thunderstorms will spread across northeast Illinois and northwest Indiana Saturday morning, with the strongest activity expected between 6 a.m. and 2 p.m. The National Weather Service warns the primary concern is locally heavy rainfall that could trigger isolated flash flooding in urban and low-lying areas.
According to the NWS Chicago office, scattered showers will develop around daybreak before storm coverage expands by mid-morning. Some storms may produce small hail and wind gusts strong enough to knock down branches or blow around unsecured outdoor items. Average storm motion is to the southeast at about 30 mph, increasing the risk for quick-moving downpours.
Drivers in Chicago, Aurora, and Gary should watch for ponding on roads and avoid attempting to cross flooded streets. Localized stream and creek rises are also possible, particularly near the Fox River Valley and along smaller tributaries feeding into Lake Michigan.
Officials urge residents to stay weather-aware throughout the morning, as additional advisories may be issued if flooding develops. Conditions should gradually improve by mid-afternoon, though lingering showers may persist.
