Southern Wisconsin severe storms, heavy rain, flooding possible

Southern Wisconsin is dealing with yet another active weather day as thunderstorms push through the region. 

The National Weather Service had issued a severe thunderstorm watch for southeast Wisconsin, which has since been canceled.

A severe thunderstorm warning was in effect until 1:15 p.m. for Jefferson County, and 1:45 p.m. for Waukesha County.

Severe thunderstorm watch (Aug. 18, 2025)

Monitoring storms

What we know:

A line of storms moved into Iowa County late Monday morning, but limited instability kept the risk of widespread severe weather lower than expected for the morning hours. However, a few storms could produce gusty winds or a brief spin-up later Monday and Monday night, mainly along the Wisconsin–Illinois border where sunshine is helping the atmosphere recover.

Storm Risks Today:

Damaging Winds: Stronger storms possible with wind gusts exceeding 55mph.

Heavy Rain: With tropical moisture in place and already saturated ground, multiple rounds of storms could trigger localized flooding in cities and rivers.

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Lightning: Remains a risk for outdoor workers, travelers, and events.

Storm Impacts:

Commutes: Rain and storms could slow afternoon/evening drive, especially south of I-94.

Air Travel: Potential delays if storms redevelop near Milwaukee or Chicago corridors.

Outdoor Events: Lightning and gusty winds remain risks for fairs, festivals, and sports.

Flooding: Localized urban flooding possible with repeated downpours; rivers may rise.

Lake Michigan: Waves 3–6 feet create dangerous swimming and boating conditions.

What's next:

Storm chances continue into early Tuesday morning as another disturbance swings through the region, but the activity should clear by late evening with the passing cold front. 

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Drier, cooler air arrives midweek, bringing highs in the 70s and lower humidity.

The Source: The information in this post was provided by the FOX6 Weather Experts, National Weather Service and SPC.

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