“When there’s a strong El Niño signal, we are warmer than normal, which we have seen throughout this winter,” Patterson said. “We have broken multiple high temperature records and high minimum temperatures as well.”
Patterson said there were damage reports in Evansville, Edgerton and Albany, which are rural communities south of Madison.
No major injuries were reported, Patterson said.
It wasn’t immediately clear if all the damage was from a single tornado or if multiple twisters had struck in Wisconsin. Patterson said National Weather Service crews visited damage sites on Friday to assess and classify the strength of the tornado on the Enhanced Fujita Scale.
“The tornado track near Evansville to SW Jefferson Co is a high end EF2,” the weather service said in an X post Friday afternoon.
Scott Lindstrom, a scientist at the University of Wisconsin-Madison Cooperative Institute for Meteorological Satellite Studies, said it was the strongest tornado in Wisconsin since August 2021 and that it had a relatively long track.
Lindstrom said the event was unusual because a clear sky preceded the twister, which developed just after sundown.
Wisconsin has seen winter tornadoes before, including three in January.