Hydrologic Outlook issued January 18 at 9:12AM CST by NWS Chicago IL

ESFLOT

Favorable conditions for river ice development and possible ice jams
are expected tonight through early next week, impacting the
Rock, Fox, Des Plaines, and Kankakee river basins.

Bitterly cold temperatures will return to the region tonight and
persist through early next week. This will make conditions favorable
for the rapid formation of river ice on area rivers and tributaries.
River ice spotters and river gauge data indicate that most area
rivers already have some areas of heavy river ice including a few
minor ice jams. New ice jams will be possible along the Rock, Fox,
Des Plaines, and Kankakee rivers, including their tributaries. Any
ice jam that develops will have the potential to cause rises on area
rivers with little warning and isolated areas of flooding are
possible.

This outlook means that elevated water levels and potential impacts
are possible, but not yet certain. Persons along area rivers should
continue to monitor the latest forecasts into next week.

This product will be updated by Sunday afternoon.