Thunderstorm Wind in Cumberland County, Illinois

Several trees and tree branches were blown down.

A cluster of thunderstorms that initiated during the night of June 28th across the Central Plains entered west-central Illinois by the late morning of June 29th. Aided by an increasingly unstable airmass characterized by CAPE values of 3000-4000J/kg and a 30-40kt mid-level jet streak, the storms became linear in nature and began racing east-southeastward across central Illinois. Widespread wind gusts of 60-80mph were observed along the line, with localized corridors of even higher gusts. The highest measured gust of 101 mph came from a personal weather station near Taylorville that took a direct hit from a tornado. A total of seven tornadoes were embedded within the line of storms, including an EF-2 tornado near Curran in Sangamon County. The high winds caused extensive tree and power line damage, leading to power loss for over 200,000 customers. Some people in the Springfield area were without power for nearly a week before all lines were restored. The winds impacted all of central and southeast Illinois, but were most concentrated between the I-74 and I-70 corridors. Once the line of storms dropped into the Ohio River Valley, additional severe cells fired along the trailing outflow boundary south of I-70 during the late afternoon. These storms produced hail as large as 2 inches in diameter across parts of Clay, Richland, and Lawrence counties.