South to southwest winds today will bring a very warm and humid airmass into the region. This very warm and humid airmass will linger tonight into Saturday evening, before a cold front moves through the area.
Highs today and Saturday are expected to reach the upper 80s to lower 90s. Cooler temperatures are expected today near Lake Michigan around and north of Port Washington, with onshore winds.
The combination of the very warm and humid conditions will bring heat index values into the lower to mid 90s today, and the mid to upper 90s on Saturday. Plan ahead for the very warm and humid conditions. Severe Storms Possible Tonight And Again Saturday Afternoon/Evening:
The very warm and humid conditions today into Saturday will allow for unstable conditions to develop across the area. A line of thunderstorms is expected to develop across northwest Wisconsin into central Minnesota later today, then slide southeastward across southern Wisconsin later this evening and overnight. There will be enough wind shear in place across the area to combine with the unstable conditions to bring the possibility of severe thunderstorms.
To keep up with the latest weather visit National Weather Service Sullivan WI
Here is a heat index chart to show heat index values and their risk levels: