This alert expired on 2 September 2026 at 23:45 UTC. It is kept here as a record.
No stronger detection stands among the 34 recorded within 20 km of this point since 4 April 2026 — 3 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Tornado Warning issued September 2 at 7:00PM EDT until September 2 at 7:45PM EDT by NWS Detroit/Pontiac MI
An estimated 291,707 people live within 50 km of this point.
Nearby, since 4 April 2026
- May 19, 2026 · score 43 · 4.2 km
- September 3, 2026 · score 49 · 5.2 km
- September 2, 2026 · score 67 · 5.5 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 67 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 | Critical |
| Calamity Score (ours) | 67 / 100 |
| Our confidence | 81% |
| Coordinates | 42.9043, -82.5736 |
| Nearest City | Port Huron (14 km) |
| Population Exposed | 291.7K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-09-02T23:00:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.6e2f5bacd88779d852a3b8f25851d17739f5f7ae.001.1 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | St. Clair, MI |
| Headline | Tornado Warning issued September 2 at 7:00PM EDT until September 2 at 7:45PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-09-02T19:45:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
Safety Information
If a tornado warning is issued: go to a basement or an interior room on the lowest floor, away from windows. A vehicle and a mobile home are not shelter. Cover your head and neck. Wait for the official all-clear before going outside, and watch for downed power lines and gas leaks afterwards.
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 Port Huron?
Calamity.live data shows a weather event with CalamityScore 67/100, near Port Huron (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.