Monday brought a very warm and sticky airmass into the Upper Midwest. A cold front moved through during the day on Monday and became the trigger for severe thunderstorms in Western Wisconsin. They were fueled by very humid dewpoints that got as high as the mid 70s for a time on Monday afternoon. Aloft, the winds were favorable for rotating supercell thunderstorms. We saw several that day. Some
There were 5 separate funnel clouds that were confirmed in the region. One of the funnels did end up touching the ground. The EF-0 tornado was on the ground for only 5 miles beginning in the marshland along the Mississippi River and tracking a bit over a mile into the Trempealeau Wildlife Refuge near Winona, MN. Its max width was 40 mph. Below is a look at the track of the twister and a picture taken when it was over the water. Both images are courtesy of the La Crosse National Weather Service.
Only a couple days later another round of severe weather moved through parts of Western Wisconsin. The big issue this time around was hail. Below is a look at the storm that caused the most trouble. This is the radar timelapse from the La Crosse National Weather Service. It was a severe thunderstorm from Fillmore Co., MN to Monroe Co., WI. Hardest hit was the La Crosse and Onalaska area.
There were several reports of hail ranging in size from eggs to tennis balls. Below is a look at some impressive hail that was found in Onalaska and sent into the National Weather Service.