Mid-summer like weather pattern in control for now. Forecast models are struggling with rain chances because of the dependency on convective precipitation. The upper level pattern is super mushy for May.
Scattered thunderstorms are likely overnight in northwest Wisconsin. This activity will produce an outflow boundary Friday morning in northern Wisconsin. Additional t-storm development is likely across Wisconsin Friday afternoon and evening along that boundary. These storms would press into the eastern half of Wisconsin late Fri Afternoon. The cold front will remain stuck in Minnesota or far northwest Wisconsin.
On Friday/Fri PM, models show storm chances across the entire state. I imagine this will become clearer as forcing mechanisms become clearer tomorrow morning. There is a very weak 500mb shortwave working over the top which makes me baised towards northern Wisconsin. As for severe potential, thermodynamics are supportive of a handful of severe damaging wind or hail threat. Overall dynamics are weak. Wind fields are veered with bulk shear in the 30kt range, so there is potential for organization. I still expect storms to go outflow dominant quickly. If storms can develop a cold pool and complex-out then that would be the worst case scenario (relative to the overall threat) tomorrow night.
High temperatures will reach the 90s across Wisconsin this weekend, potentially lasting through Memorial Day. Very warm, dare I say hot? Humid too on Saturday.