MILWAUKEE (AP) — Strong thunderstorms caused widespread damage across Wisconsin, left tens of thousands without power and triggered tornado warnings.
The severe weather stretched from the Mississippi River to Lake Michigan and began Wednesday evening in northwestern Wisconsin. By 2 a.m. Thursday, the numerous tornado warnings around the state had expired.
The National Weather Service surveyed hard-hit areas in southeastern Wisconsin and confirmed it was a tornado, probably rated EF1, that caused damage around the Jefferson County community of Concord, where the storm toppled farm buildings and left a path of destruction. Cows could be seen grazing among debris that landed in farm fields.
Gov. Tony Evers signed a declaration imposing a state of emergency in Wisconsin. Evers' order directs state agencies to help those affected by the storms. It also allows the Wisconsin National Guard to be activated to support local authorities with recovery efforts.
Meteorologist Denny VanCleve in Sullivan said there's a good chance it was a tornado, or possibly two, that caused widespread damage.
The weather service Wednesday warned the severe weather sweeping across upper Midwest states could include hurricane-force winds and tornadoes and develop into a derecho — a rare type of storm often described as an inland hurricane.
"If not a derecho, it was close," VanCleve said. "You need wind damage more than 240 miles long and gusts of 58 mph for most of its length."
A determination on whether the storm could be classified as a derecho would be made later, VanCleve said.
Utility crews worked to restore service to thousands of power customers. Electricity was knocked out to about 90,000 customers across Wisconsin, according to the tracking website PowerOutage, US.
The tornado warnings started in Wausau and eventually were issued for Waukesha, Jefferson and Milwaukee counties around 1 a.m. Thursday.
The National Weather Service placed nearly the entire state of Wisconsin under a severe thunderstorm watch until 2 a.m. Thursday.
A 70 mph wind gust was reported at 8:40 p.m. Wednesday in Merrill in Lincoln County, according to the weather service. Numerous trees and power lines were reported down in Merrill.
A 78 mph wind gust was reported at Weston in Marathon County at 9 p.m., according to the weather service. Sustained winds of 74 mph are required for a Category 1 hurricane.