9:00 UPDATE: The severe threat has ended. The Severe Thunderstorm Watch that had been issued was canceled early.
8:10pm UPDATE: A SEVERE THUNDERSTORM WARNING remains in effect for Walworth County until 8:45pm. The storm was located near Lake Geneva and was moving southeast at 35 mph. Ping pong ball sized and 60 mph wind gusts are possible.
I’m also keeping an eye on the storm just northeast of Beloit, WI. It has grown rather quickly and will need to be watched as it moves closer to the Boone County line.
7:15pm UPDATE: The Severe Thunderstorm Warning that had been issued for northeast Rock and northwest Walworth counties has been allowed to expire. The storm has weakened a bit as it has moved further into Walworth County. Heavy rainfall and wind gusts in excess of 40 mph remain possible, but right now the storm has fallen below severe limits.
6:35PM UPDATE: A SEVERE THUNDERSTORM WARNING has been issued for northeast Rock and northwest Walworth counties until 7:15pm. A severe storm located near Whitewater, WI is moving to the southeast at 25 mph and capable of producing 60 mph wind gusts and quarter sized hail. If you are in the path of the storm, seek shelter.
A SEVERE THUNDERSTORM WATCH has just been issued for Boone and McHenry counties in northern Illinois, and for Green, Rock, and Walworth counties in Wisconsin until 10pm. Thunderstorms have started to rapidly develop in Wisconsin along a lake breeze moving through Milwaukee and a cold front just north of Madison.
The storms near Milwaukee will continue to move southeast, over Lake Michigan, but the storms located near Madison, WI could impact parts of the viewing area within the next hour or two.
The current storm motion is to the southeast, placing areas along and east of I-39 having the best chance for isolated severe thunderstorms. Damaging wind gusts and torrential downpours will be the biggest threats with any severe storm that develops. Small hail may also occur.
Our window for thunderstorms will take us through 10pm, with drier skies expected overnight. it’ll still remain humid through Friday with temperatures back into the upper 80s and the heat index in the low 90s.