Thunderstorm Wind in Shelby County, Illinois

A large tree was split.

An upper-level disturbance interacting with an outflow boundary triggered scattered showers and thunderstorms in the Illinois River Valley during the morning of July 8th. This initial band of showers tended to dissipate toward midday: however, as the atmosphere destabilized during peak heating, an uptick in convective development was noted further east along and east of I-55 by late afternoon into the evening. With ample deep-layer moisture in place as evidenced by precipitable water values of 1.75-2.00, the storms that developed were efficient rain-producers. In addition, atmospheric steering winds were quite weak...leading to slow storm movement. The end result was highly variable rainfall amounts...with a few spots picking up over 3 inches in a short amount of time. One of the hardest hit locations was Bloomington-Normal in McLean County where widespread amounts of 3 to 5 inches caused flash flooding of several area streets. Further south, a few of the cells produced isolated wind damage across parts of Sangamon and Shelby counties.