Interstate 90 was closed for more than three hours due to trailers being blown onto their sides, but no deaths or major injuries were reported.
“The tornado took down multiple trees, power lines, and barns,” the county’s sheriff’s office wrote in a Facebook post. “There is wide spread power outage and damage to a number of homes as well.”
In the meantime, officials asked people to avoid the area because many roads remain impassible and littered with debris from the damage.
Tomah is about 100 miles northwest of Madison, Wisconsin.
Mile Bluff Medical Center in Mauston, Wisconsin, said a storm passed through its area and damaged trees and vehicles, though the facility experienced minor damage. The storm also prompted patients, residents and staff members to shelter in place.
And while the medical center doesn’t anticipate appointment interruptions Thursday, it noted access to its emergency room is limited.
“There are numerous roads that are impassible because of these hazards,” the office said.
Temperatures in Milwaukee on Wednesday reached up to 95 degrees — nearly 20 degrees above average — with high humidity, according to NWS.
The Milwaukee County Medical Examiner’s Office said Wednesday two heat-related deaths are under investigation, and autopsy results are expected Thursday. CNN has reached out to the medical examiner’s office for additional information.
CNN’s Chris Boyette and Robert Shackelford contributed to this report.