Along with the potential for severe weather Saturday, the National Weather Service in Chicago issued a flood watch until Tuesday evening for the Illinois River in Ottawa, or from Heritage Harbor east of Ottawa downstream to Starved Rock Lock and Dam.
Storms are expected to begin Friday and continue into Saturday night, some of them severe, with the potential for tornadoes.
Minor flooding is possible. Flood stage may be reached by Sunday evening.
The roadway entrance to Allen Park in Ottawa may flood and the west boat ramp may become inundated with water. Backwater may cause the Fox River to reach its full near OSF St. Elizabeth Medical Center.
A flood watch also has been issued for the river near La Salle. Forecasted to reach 2 feet above flood stage, the lower parking lot at Starved Rock State Park may flood. The park has been closed due to the coronavirus outbreak.