Updated: Tuesday, May 21, 7:25 pm:
A tornado watch has been expanded to include all of southeastern Wisconsin.
Multiple tornado warnings were issued for a series of storms moving northeast at 50 mph. Embedded rotating areas will continue to be a concern as this storm moves into southeastern Wisconsin over the next several hours.
Listen to CBS 58 radio coverage.
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Updated: Tuesday, May 21, 6:35 pm:
Fond du Lac County has been added to a tornado watch through midnight.
Scattered severe thunderstorms are developing ahead of a major line of severe storms near the Mississippi River. A rotating area within the squall line has prompted a tornado warning between La Crosse and Eau Claire.
The severe window hours for southeastern Wisconsin remain the same: 8 to 11 p.m.
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Updated: May 21, 2024 at 5:30 pm
The SPC has issued a tornado warning until midnight for most of our area. At this time, this does not include our Lakeside County due to the uncertainty of the warm front.
Showers and storms are expected to develop in southwestern Wisconsin late this afternoon and early evening. The line is expected to pass through our area between 8pm and 11pm.
All types of severe weather are expected. Damaging winds, large hail and isolated tornadoes are all possible.
Now is the time to charge your devices before the power goes out.
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Update time: 3:00 pm on May 21, 2024
All eyes are on the warm front covering southern Wisconsin. Air masses north of the border are relatively stable and cool. Note that temperatures in northern Illinois are approaching 90 degrees.
There is a lot of instability south of the warm front. We call this region the warm region. The warm front is expected to move further north during the evening hours; however, we will see how the lakes change some of this.
Showers and storms are expected to develop in southwestern Wisconsin late this afternoon and early evening. The line is expected to pass through our area between 8pm and 11pm.
I expect to watch later tonight.
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Updated: May 21, 2024 1:30 pm
A severe cell develops rapidly and collapses.
Dane County did receive hail a little larger than an inch in diameter. This cell shows how unstable our air mass is today. Any other storms that develop this afternoon should remain isolated, with persistent, widespread storms still intact heading into the evening.
Update time: noon on May 21, 2024
We will be quiet at noon today. Fog persists in downtown Milwaukee. However, things are getting active in our west. Here is the latest radar image with current alerts:
Even with the rain and storms in western Wisconsin, the track is basically going to take it north of our region this afternoon. As it stands, this setup will likely keep us quiet for the evening commute before severe storms with high wind potential will gather together and sweep across the viewing area from west to east. The best time to visit the lakeside is after 8 pm.
Updated: May 21, 2024 9:48 am
The morning's dense fog has dissipated across much of southeastern Wisconsin. Dew points will remain high throughout the day, so expect to feel some humidity. Our storms will continue Tuesday night. A few afternoon storms are possible, but so far the morning rain has stayed in our western areas, with only a few showers in Dodge and Fond du Lac counties. Storms in central Iowa will need to be watched to see if they bunch up as they move into southwestern Wisconsin.
Here is the radar image updated over time:
While the chance of storms remains low during the day, we still have a chance of rain from 7pm to midnight tonight. These will be fast-moving storms bringing damaging winds and some tornadoes as well as hail and heavy rain.
The Enhanced Level 3 Risk for Severe Weather remains unchanged throughout southeastern Wisconsin. The southwest region of the state has been classified as level 4 moderate risk. We're used to Level 1 and 2 events, but Level 3 and 4 events are even rarer. At that time, the chance for storms will become more frequent and widespread, including some severe storms, with the potential for more tornadoes, especially strong Category 4 moderate risk tornadoes.
The remainder of the forecast outlined below, including storm threats, is proceeding as planned.
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Published: May 21, 2024 5:04 AM
There will be plenty of scattered showers and storms on Monday, with many strong storms but few severe storms. A storm in Fond du Lac County caused some damage Monday morning, but otherwise the high winds were relatively calm. But we did get a lot of rain. Much of southeastern Wisconsin received between 1 and 2 inches of rain on Monday.
All this rain combined with steadily high dew points and calm winds is leading to a foggy start to Tuesday. A dense fog warning is in effect throughout southeastern Wisconsin until 10 a.m. Tuesday. Visibility was sometimes only a few hundred feet.
Morning fog won't have much of an impact on Tuesday's storm forecast. Continued rain and storms are moving across much of the upper Midwest Tuesday morning and are starting to reach Wisconsin. There are questions about whether these storms will persist as they move into southeastern Wisconsin, but overall, rain chances look pretty limited Tuesday morning and afternoon. However, any storms that form during the day could still be severe, with the threat of hail and strong winds.
The best chance for severe weather in southeastern Wisconsin remains Tuesday night. A series of strong and potentially severe storms will develop over southeastern Wisconsin, primarily after 7 PM, ahead of a cold front. The storm potential will continue until midnight, when the storm line moves over Lake Michigan.
The risk of severe is elevated Tuesday, especially in southeastern Wisconsin. A rare Category 4 severe weather risk has expanded to include parts of southwestern Wisconsin. These counties have the highest probability of tornadoes. Locally, all of southeastern Wisconsin is under enhanced risk level 3.
Damaging winds will be the main threat for any severe storms moving along the storm line Tuesday night. Wind gusts could reach 75-90 mph, causing downed trees and widespread power outages. Many communities also sound warnings for wind gusts over 80 mph, which can cause as much damage as a weak tornado, so if you do hear a tornado siren or get a loud alert on your phone, it could be damage Sexual wind or tornado. The threat of tornadoes is also relatively high, especially the tornadoes we typically see in southeastern Wisconsin. Some tornadoes in southwestern Wisconsin could be strong, and we'll see if that threat continues into southeastern Wisconsin. There is also a risk of large hail and localized flooding.
Rainfall totals Tuesday will hover around an inch. However, some communities may see more from severe thunderstorms.
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