The Flood Warning goes from Thursday night through Saturday morning.
Forecasters say the river is now expected to crest at around 15.5 feet early Friday afternoon, which is in the major flood stage.
The river is expected to then fall below flood stage early Saturday morning.
At 15.5 feet, several businesses could be impacted downtown, with many roads near the river closed.
County Road 236 to State Route 568 would be inundated.
The following streets are likely to be flooded, Main Cross Street from Western to Township Road 180, Broad Street, streets along Eagle Creek from Central to Rockside and streets along Lye Creek from Wedgewood to Strong Avenue.
The picture above of the Blanchard River in Findlay was taken at around 12:30 Thursday afternoon.
Click here for the latest river levels and forecast.