National Weather Service United States Department of Commerce


In the afternoon and evening of Wednesday, May 17, 2017, three rounds of severe thunderstorms impacted southern Wisconsin. In the mid afternoon, a supercell developed in Iowa county, moved through Sauk, Dane, Columbia, Marquette, and Green Lake counties, and dropped up to quarter sized hail.

By early evening, another intense thunderstorm moved out of Illinois and through Rock, Jefferson, Waukesha, Dodge, and Washington counties and produced damaging  winds. Near the town of Darien in Rock county, winds were estimated at 80 mph by a NWS storm survey. A second storm then developed in eastern Waukesha county, moved into Milwaukee county, and produced strong winds.

The third round of storms was in a north-south oriented line that moved in from the west and swept across all of southern Wisconsin. They were generally the strongest closer to the Mississippi River before gradually weakening as they approached Lake Michigan. The exception was in Walworth county, where a supercell developed in Illinois ahead of the line, produced a tornado in extreme northern Illinois, and then crossed the state line and produced damaging winds in southeast Walworth county.

Image Image Image
Radar - Round 1 Radar - Round 2 Radar - Round 3
nws logo Media use of NWS Web News Stories is encouraged!
Please acknowledge the NWS as the source of any news information accessed from this site.
nws logo