This alert expired on 4 September 2026 at 13:15 UTC. It is kept here as a record.
It is the 11th strongest of the 33 detections recorded within 20 km of this point since 17 March 2026. The last comparable one was on 3 September 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 4 at 8:24AM EDT until September 4 at 9:15AM EDT by NWS Grand Rapids MI
An estimated 301,191 people live within 50 km of this point.
Nearby, since 17 March 2026
- September 3, 2026 · score 37 · 3.8 km
- July 3, 2026 · score 43 · 4.7 km
- July 3, 2026 · score 43 · 5.8 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.
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 | 81% |
| Coordinates | 42.5143, -84.9129 |
| Nearest City | Battle Creek (31 km) |
| Population Exposed | 301.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-04T12:24:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.a4fb9274d729300e5a6eaaf6faee94e4ca5f7890.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Eaton, MI |
| Headline | Severe Thunderstorm Warning issued September 4 at 8:24AM EDT until September 4 at 9:15AM EDT by NWS Grand Rapids MI |
| Expires | 2026-09-04T09:15:00-04:00 |
| SenderName | NWS Grand Rapids MI |
| HasExactCoords | true |
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 in this area?
Calamity.live data shows a weather event with CalamityScore 37/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.