This alert expired on 2 September 2026 at 05:21 UTC. It is kept here as a record.
It is the 3rd strongest of the 55 detections recorded within 20 km of this point since 15 March 2026. The last comparable one was on 31 July 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 2 at 12:11AM CDT until September 2 at 12:15AM CDT by NWS Twin Cities/Chanhassen MN
An estimated 162,513 people live within 50 km of this point.
Nearby, since 15 March 2026
- September 2, 2026 · score 49 · 17.6 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 81 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 37 / 100 |
| Our confidence | 81% |
| Coordinates | 43.9764, -92.7245 |
| Nearest City | Rochester (21 km) |
| Population Exposed | 162.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-02T05:11:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.3543415d8fb7f430227c8e23a94aaf19536a90c3.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Steele, MN; Waseca, MN; Blue Earth, MN; Brown, MN; Faribault, MN; Martin, MN; Nicollet, MN; Watonwan, MN; La Crosse, WI; Trempealeau, WI and 1 more areas |
| Headline | Severe Thunderstorm Warning issued September 2 at 12:11AM CDT until September 2 at 12:15AM CDT by NWS Twin Cities/Chanhassen MN |
| Expires | 2026-09-02T00:21:00-05:00 |
| SenderName | NWS Twin Cities/Chanhassen MN |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.3543415d8fb7f430227c8e23a94aaf19536a90c3.001.1","noaa_urn:oid:2.49.0.1.840.0.3666bc15ca90b269c84cb02eb473f986ddfec037.001.1","noaa_urn:oid:2.49.0.1.840.0.4afc8ec7d875f9397a22351e44184435a769090a.001.1","noaa_urn:oid:2.49.0.1.840.0.2ab0b8c3ada6114886336ba9b24e98ec07f778ea.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 10 February 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 Rochester?
Calamity.live data shows a weather event with CalamityScore 37/100, near Rochester (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.