Flash Flood in Piatt County, Illinois

Periods of thunderstorms with heavy rainfall produced rain rates of 1 to 2.5 inches for at least two hours from 0630-0830 LST in northern Piatt County. The highest rain totals ranged between 5.00 to 7.00 inches along and north of U.S. Highway 150, including the city of Mansfield and the village of Blue Ridge. Nearly all rural roads in northern Piatt County were flooded with at least a foot of water. County Road 2 from Mansfield to Blue Ridge sustained damage from the flooding. A five mile stretch of U.S. Highway 150 through Mansfield was closed due to flooding. Parts of Interstate 74 from milepost 164 to 168 were impassable. Many homes in Mansfield also had significant basement flooding.

An upper-level disturbance interacting with a very moist airmass triggered a cluster of thunderstorms across east-central Illinois during the morning of July 12th. The storms were efficient rain-producers and tended to back-build over the same locations, resulting in 4 to 6 inches of rain from southeastern McLean County across northern Piatt County into central and northern Champaign County. As much as 7 inches of rain was reported in northwestern Champaign County around Mahomet. As a result of the very heavy rain falling in a short amount of time, widespread flash-flooding occurred. Numerous roads were closed due to flooding.