EF1 tornado in Marquette County, Wisconsin

The tornado started near Grouse Rd east of Briggsville and then tracked to the northeast. The worst damage was to an onion farm south of County Road O. The tornado crossed Interstate 39 and dissipated near County Road CX. Storm chaser videos and photos along with security camera footage from the onion farm confirm the tornado.

Numerous severe thunderstorms developed across southern Wisconsin during the afternoon and evening hours as a wave of low pressure moved across a stationary front over the region. Two main supercell thunderstorms developed along and north of Interstate 94 between Madison and Milwaukee, which produced softball sized hail and an EF-2 tornado. These storms would later merge while a squall line developed in south central Wisconsin which would then track through southeast Wisconsin. Elsewhere, a few storms had brief rotations show up, producing a tornado near Endeavor. The supercell thunderstorms and squall line trained over the same locations producing flash flooding mainly in urban areas.