Chicago, IL – Another round of torrential thunderstorms could bring significant flash flooding and damaging winds to parts of Illinois late Friday night into Saturday morning, with areas already soaked by heavy rain facing the greatest danger.
According to the National Weather Service in Chicago, thunderstorms may develop in lines or clusters late Friday into Saturday morning. The strongest storms could produce rainfall rates exceeding 2 inches per hour along with damaging winds capable of knocking down tree limbs.
Forecasters said some locations received 3 to 6 inches of rain Thursday night, particularly south of a Pontiac, Illinois, to Fowler, Indiana, line. Those saturated areas will be especially vulnerable if additional heavy rain moves across the same locations.
Flash flooding could become significant, potentially flooding roads and structures while causing rapid rises along streams, creeks and rivers, the Weather Service said. The threat is expected to be widespread across the region but increases toward central Illinois and areas southwest of the Chicago metro.
A Flood Watch remained in effect through 10 a.m. Friday for portions of the region southwest of Chicago. Forecasters said another Flood Watch may be needed for at least part of the area late Friday night into Saturday morning.
Storm placement remains uncertain because the location and timing will depend on where boundaries from earlier thunderstorms settle. Subsequent storms could also shift those boundaries.
Residents near rivers and flood-prone locations should monitor conditions and prepare for possible flooding. Drivers should never attempt to cross a flooded roadway, particularly at night when water depth can be difficult to judge.
The Weather Service urges residents to monitor updated forecasts and have multiple ways to receive weather warnings as thunderstorms develop overnight.
