EF3 Tornado — Grundy, Illinois

2015-06-22 · near Paytonville, Grundy, Illinois

Event narrative

The tornado touched down near Higgins Road and Dupont Road where softwood trees were snapped. The tornado moved east-southeast where trees and power poles were snapped along N Gorman Road. The most significant damage was noted as the tornado crossed S Carbon Hill Road just south of Division Street, entering Coal City. Dozens of homes were heavily damaged in Coal City with three completely destroyed. Two of these homes were well built and had at least part of their structure bolted down to the foundation with bolts secured by nuts. Two high tension metal trusses were downed including one that was crumpled along Hunters Run. Hundreds of trees were snapped or uprooted. Numerous utility poles were downed. Peak winds were estimated to be 160 mph with a max width of three quarters of a mile. The tornado continued into Will County. (Tornado 8a of 10).

Wider weather episode

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.

View location on OpenStreetMap → (41.3082, -88.3823)

Source: NOAA Storm Events Database, event_id 590644. Narrative written by the NWS forecast office that issued the report.