This alert expired on 3 September 2026 at 13:45 UTC. It is kept here as a record.
It is the 15th strongest of the 59 detections recorded within 20 km of this point since 16 March 2026. The last comparable one was on 9 August 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 3 at 8:05AM CDT until September 3 at 8:45AM CDT by NWS Milwaukee/Sullivan WI
An estimated 480,511 people live within 50 km of this point.
Nearby, since 16 March 2026
- September 3, 2026 · score 37 · 4.1 km
- August 9, 2026 · score 43 · 17.4 km
- June 24, 2026 · score 43 · 17.5 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 37 out of 100, at 82 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 37 / 100 |
| Our confidence | 82% |
| Coordinates | 43.0920, -88.9425 |
| Nearest City | Watertown (20 km) |
| Population Exposed | 480.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-03T13:05:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.f15afd0c9ba2c48b3628d76f91db593627b936a6.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Dane, WI; Green, WI; Iowa, WI; Lafayette, WI; Milwaukee, WI; Ozaukee, WI; Washington, WI; Waukesha, WI |
| Headline | Severe Thunderstorm Warning issued September 3 at 8:05AM CDT until September 3 at 8:45AM CDT by NWS Milwaukee/Sullivan WI |
| Expires | 2026-09-03T08:45:00-05:00 |
| SenderName | NWS Milwaukee/Sullivan WI |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.f15afd0c9ba2c48b3628d76f91db593627b936a6.001.1","noaa_urn:oid:2.49.0.1.840.0.24b0adac7bff2f489844ea1f2bbb06a39c14227b.001.1"] |
Safety Information
Always follow official guidance from your local emergency management agency. This platform provides scientific monitoring data and is not a substitute for official warnings. If you are in immediate danger, contact your local emergency number.
Series begins 8 March 2026. Comparisons refer to that period only. Collection gap: 14-26 August 2026.
This data is aggregated algorithmically from scientific sources. Not a replacement for official emergency warnings.
Want to know when something happens near Watertown?
Calamity.live data shows a weather event with CalamityScore 37/100, near Watertown (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.