Heavy rainfall overnight has increased the potential for flash flooding in north-central and northeast Iowa today (Wednesday, June 22, 2016).

Flash flood warnings are posted for Black Hawk, Bremer, Butler and Grundy counties until 7 a.m. A flash flood warning is also posted for Benton County until 7:30 a.m. and for Tama County until 8:45 a.m.

Waterloo, Cedar Falls, Waverly, Grundy Center, Allison, Vinton, and Traer are among the locations where rivers and streams are expected to rise rapidly. Other cities in the warned area are Aplington, Clarksville, Denver Dike, Elk Run Heights, Evansdale, Greene, Hudson, Jesup, La Porte City, Parkersburg, Reinbeck, Sumner and Tripoli.

Overnight rainfall amounts across the region ranged between two and four inches, with higher amounts being reported in some isolated areas. The National Weather Service is predicting the excessive runoff from the heavy rain will cause flooding of small creeks and streams, country roads, farmland, and other low-lying spots.

Outside the warned area, a flash flood watch is posted for several area counties until 10 a.m. Wednesday.

While rain is expected to continue after sunrise, the threat for severe weather has diminished in north-central and northeast Iowa. A severe thunderstorm watch that was posted until 10 a.m. Wednesday for several area counties has been dropped.

According to the Storm Prediction Center in Norman, Okla., the threat for severe weather returns to much of the region by mid-afternoon on Wednesday.