The National Weather Service has issued a flood warning for urban areas and small streams. It will be in effect until 9:45 a.m. Friday.
The warning includes Allen, Wells, Huntington, Adams, Wabash, Whitley and Kosciusko counties.
Radar indicates heavy, widespread rainfall. One to two inches of rain is expected overnight, the weather service said.
Small streams and creeks, including Spy Run Creek in Fort Wayne, will likely overflow, the report said.
Motorists are encouraged to be extremely cautious at night, as it is harder to spot flooded areas or flash floods, the report said.