After starting out the holiday weekend with some rain, another round of showers and thunderstorms is expected into Labor Day.
A lot will depend on the timing of the rain, how long it lingers, and the position of a cold front that will, at least temporarily, provide a break in the heat and humidity.
Showers and thunderstorms have developed in Iowa and Minnesota ahead of a cold front that is moving eastward from Nebraska and Iowa. Some of these thunderstorms may be severe to the west of the Mississippi River, but by the time the thunderstorms reach Wisconsin, they should be weakening in the cooler overnight air.
The showers and thunderstorms will move through Wisconsin on Monday morning, moving into central Wisconsin and Lake Michigan by early afternoon. However, the cold front will just be reaching western Wisconsin at that time. It's possible that the clouds and precipitation from the morning may keep the atmosphere stable enough that little precipitation may develop ahead of the cold front before it moves to our south and east by early evening.
If clouds thin out and the atmosphere has a chance to warm up to where temperatures reach the lower to middle 80s, then thunderstorms will become more likely in the afternoon. It may even be possible for a few thunderstorms to become severe, with the threats including high winds, hail, and locally heavy rainfall. In any event, Monday afternoon thunderstorms will be spottier in coverage, and many people may see little or no rainfall.
The threat for showers, thunderstorms, and severe weather (if any) will end by late afternoon or early evening on Monday as the cold front moves away to the southeast. While there is a slight chance for afternoon showers on Tuesday, it should be a little cooler and less humid as well.
For the rest of the week, warm and humid weather will return on Wednesday and last into Thursday and possibly Friday as well. Scattered showers and thunderstorms are expected from Wednesday night into Thursday and Friday as a warm front lifts temperatures into the middle to upper 80s on Thursday, and a cold front drops them back into the lower 80s on Friday.