Several severe thunderstorms affected south central Wisconsin Sunday and Sunday night producing damaging wind gusts. Here is a link to the local storm reports that have been received at the National Weather Service office near Sullivan.
Nearby low pressure in Minnesota and an eastward extending warm front will continue to bring scattered to numerous thunderstorms to southern Wisconsin tonight into Tuesday. Warm south winds ahead of the low will bring a plume of moisture into southern Wisconsin late this afternoon. Also, strong vertical wind shear associated with the low pressure system will result in an increased liklihood of strong to severe thunderstorms tonight.
Damaging winds will be the the main threat tonight, and large hail will be possible. There is a lower threat of tornadoes due to the later timing of this convection. All of southern Wisconsin is under a slight risk for severe thunderstorms through tonight. The low pressure system will remain nearby into Tuesday as well, continuing the slight risk for severe thunderstorms.
National Weather Service - Milwaukee/Sullivan