Localized rainfall rates of 3 inches per hour are possible for some parts of the Chicago area overnight into Saturday, and a flood watch has already been issued.
The flood watch is in effect for Ogle, Lee, DeKalb, Kane, DuPage, Kendall, Cook and Will counties from 10 p.m. Friday to 10 a.m. Saturday.
According to the weather service, another round of torrential rain-producing showers and storms is possible Friday night.
The weather service said creeks and streams may rise out of their banks, and flooding may occur in poor drainage and urban areas.
Locally damaging winds will also be possible, the weather service said. The highest threat for severe weather is along and south of Interstate 80.
"A strong to severe storm cannot be ruled out Saturday night into early Sunday morning," the weather service added. "Then, additional storms may occur during the middle of next week."
Sign up for free local newsletters and alerts for the
Across Illinois Patch
Patch.com is the nationwide leader in hyperlocal news.
Visit Patch.com to find your town today.