EF1 tornado in La Salle County, Illinois

A tornado crossed through the center of Mendota resulting in significant tree damage. Some trees were blown down onto structures and at least one fell onto a vehicle. The tornado touched down near the intersection of Knoll Crest Drive and S Park Avenue where numerous hardwood trees were snapped. One to three inch branches were broken as the tornado crossed 13th Avenue. A large trunk was split on Washington Street. Trees were uprooted on 5th Street near 5th Avenue. Hardwood trees were snapped on N 1st Avenue, including one that fell onto a pickup truck. Maximum winds were estimated to be 105 mph. (Tornado 4 of 10).

During the evening of June 22, twelve tornadoes occurred across northern Illinois, including ten in the WFO Chicago forecast area. Ten of the twelve were spawned from a single long-lived cyclic supercell, which tracked across Whiteside, Lee, LaSalle, Grundy, Will, and Kankakee Counties. The heaviest damage was in Coal City (Grundy County) and Braidwood (Will County) which was caused by an EF-3 tornado with maximum winds of 160 mph, and the Woodhaven Campground in Sublette (Lee County) caused by an EF-2 tornado with maximum winds of 130 mph. There were 14 injuries reported. There were no fatalities. The EF-3 Coal City to Braidwood tornado was the strongest tornado in Grundy County since an F3 tornado struck on July 17, 1972. The atmosphere was primed for severe weather, with very warm, humid conditions, low pressure moving north of the region, and a strong jet stream aloft. An outflow boundary from earlier storms during the late morning and early afternoon may have been key to where the long-lived tornado-producing storm tracked. In addition to tornado and wind damage, slow moving storms brought torrential rainfall of locally up to 3 to 5 inches to portions of Lee, Grundy, Will, and Kankakee counties, resulting in widespread flash flooding. This rain fell on top of soil already saturated from repeated heavy rains over the past few weeks.