Severe Thunderstorm Warning Issued for Southeastern Wisconsin Counties

Source: NOAA · Southeastern Wisconsin

This alert is no longer in effect.

NOAA issued it on August 18, 2026, 5 days ago. Warnings of this kind stay in effect for hours to a few days, so this page is a historical record of what was issued, not a current warning. For conditions where you are right now, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia).

Areazine synthesizes this NWS weather alert directly from NOAA's official public data feed. See our methodology for full source attribution and refresh cadence.

NWS Milwaukee/Sullivan has issued a Severe Thunderstorm Warning for seven Wisconsin counties until 7:30 PM CDT on August 18, 2026.

Read this weather record in 30 seconds

Record type
Severe Thunderstorm Warning
Affected area
Southeastern Wisconsin
Issued
August 18, 2026
Issuing authority
NWS Milwaukee/Sullivan WI

Storm notices can cover different combinations of wind, hail, lightning, and rainfall. Use the original notice for the hazards and boundaries attached to this specific record.

Record status: historical. It was issued 5 days ago; use the issuing agency's live warning service for current conditions in Southeastern Wisconsin.

Alert Details

A Severe Thunderstorm Warning was issued by the National Weather Service Milwaukee/Sullivan WI at 6:23 PM CDT on August 18, 2026. The alert is effective immediately until 7:30 PM CDT.

Affected Areas

The warning covers Southwestern Ozaukee County, Northern Milwaukee County, Waukesha County, Southeastern Dane County, Southern Washington County, Jefferson County, and Southeastern Dodge County in southeastern Wisconsin. Impacted locations include Milwaukee, Waukesha, West Allis, Wauwatosa, New Berlin, Brookfield, Menomonee Falls, Muskego, Watertown, Mequon, Whitewater, Hartford, Whitefish Bay, Pewaukee, Stoughton, Fort Atkinson, Brown Deer, Grafton, Cedarburg, and Port Washington.

What You Should Do

Remain alert for a possible tornado. If you spot a tornado, go at once into the basement or a small central room in a sturdy structure. Move to an interior room on the lowest floor of a building.

Expected Conditions

At 6:23 PM CDT, severe thunderstorms were located along a line from near Jackson to near Lac La Belle to near Lake Mills to near Stoughton, moving southeast at 35 mph. Hazards include 60 mph wind gusts and penny size hail. Radar indicated. Expect damage to roofs, siding, and trees.

Timeline

The warning is in effect from 6:23 PM CDT until 7:30 PM CDT on August 18, 2026.

Original source: NOAA Official Notice ↗

All Weather Alerts →

Nationwide notices with similar length or severity timing 8

Two Areazine-derived peer sets for this NWS weather alert: nearest notices by body length and by same severity near the same agency date. Peers come from other categories so they are not the same-feed Related list above.

Frequently Asked Questions

Common questions about this NWS weather alert.

What is this NWS weather alert about?
NWS Milwaukee/Sullivan has issued a Severe Thunderstorm Warning for seven Wisconsin counties until 7:30 PM CDT on August 18, 2026.
Which agency issued this alert?
This alert was issued by NOAA. The original notice is available at the source link at the bottom of this article.
How severe is this alert?
This alert is classified as "high" severity. Take precautions and monitor for updates.
What area is affected?
This alert affects Southeastern Wisconsin. Check with NOAA for the most current geographic scope.
Where can I find more Weather Alerts updates?
Browse the full Weather Alerts feed on Areazine at areazine.com/weather/ for the latest updates from NOAA and other agencies.