Hydrologic Outlook issued January 28 at 3:36AM CST by NWS Chicago IL

ESFLOT

Significant ice coverage exists on area rivers. While
unseasonably mild temperatures this week will facilitate some
melting and breaking up of the ice, significant amounts of ice
will likely remain in many rivers late this week. A storm system
is likely to bring rainfall to the region late Thursday into
Friday. There is still a great deal of uncertainty in how much
rain will fall, but current indications are that many areas will
see at least a quarter to half inch of rain. Depending on the
track and strength of the storm system, some areas could see
heavier rainfall totals of a half inch to one inch.

The measured soil frost depth this morning remained 12 inches
with no near surface thaw yet. While there will be mild
temperatures this week, any thaw that takes place will likely
remain shallow, resulting in minimal infiltration into the ground
of rain later this week. Rather, most of the rain should runoff
into area streams and creeks resulting in an increase in
streamflow. Even a modest increase in streamflow could result in
further breakup and dislodging of river ice, leading an increased
risk of localized ice jam flooding.

This outlook means that locally elevated water levels due to ice
jams are possible, but not yet certain. Persons living in areas
prone to experience ice jam flooding, particularly along the
Kankakee, Rock, and Fox Rivers, should closely monitor later
forecasts.