Several rounds of severe storms moved through central and southeast IL on Thursday, June 29. The first round occurred before sunrise and continued into the mid-morning hours, with supercell thunderstorms that produced very large hail and heavy rainfall from Peoria into parts of eastern IL, including 3.25" hail in Tuscola. By later that morning, a large bow echo/derecho that initiated from overnight storms over the central Plains entered west-central IL, spreading east-southeast through the entire forecast area by the late afternoon hours.

Widespread, significant straight-line wind damage was reported areawide as well as a few tornadoes. This resulted in a substantial amount of tree damage, crop damage, and extensive power outages. The derecho continued to track southeast of here into southern Indiana and points beyond, producing more wind damage. The third and final round was more localized and occurred south of I-70 during the early evening hours when a few supercell thunderstorms produced large hail up to 2" in parts of Clay and Richland counties.

What is a derecho? A derecho is a widespread, long-lived wind storm that is associated with a band of rapidly moving showers or thunderstorms variously known as bow echoes, squall lines, or quasi-linear convective systems. By definition, if the wind damage swath extends more than 240 miles (about 400 kilometers) and includes wind gusts of at least 58 mph (50 kt) or greater along most of its length, then the event is classified a derecho.