This alert expired on 3 September 2026 at 16:45 UTC. It is kept here as a record.
It is the 23rd strongest of the 42 detections recorded within 20 km of this point since 15 April 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Special Marine Warning issued September 3 at 12:35PM EDT until September 3 at 12:45PM EDT by NWS Detroit/Pontiac MI
An estimated 1,143,848 people live within 50 km of this point.
Nearby, since 15 April 2026
- July 18, 2026 · score 52 · 10.2 km
- August 22, 2026 · score 52 · 11.5 km
- July 4, 2026 · score 52 · 11.6 km
How we know
Confirmed by 4 independent sources, including NOAA.
Our own score for this event is 46 out of 100, at 92 % 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) | 46 / 100 |
| Our confidence | 92% |
| Coordinates | 42.6857, -82.6395 |
| Nearest City | Mount Clemens (22 km) |
| Population Exposed | 1.1M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-03T16:35:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.64017c38d42d0c61793497a40b934c576dc08658.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | St. Clair River; Lake St. Clair Open Lake (U.S. Portion) |
| Headline | Special Marine Warning issued September 3 at 12:35PM EDT until September 3 at 12:45PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-09-03T12:45:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| Spc ReportType | wind |
| Spc Speed | UNK |
| Spc Location | 3 W Lake Orion |
| Spc County | Oakland |
| Spc State | MI |
| Spc Comments | One large healthy tree down. (DTX) |
| Iem TypeSummary | R |
| Iem Magnitude | 2.04 |
| Iem Unit | Inch |
| Iem City | 4 ENE Northeast Detroit |
| Iem County | Macomb |
| Iem State | MI |
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 Mount Clemens?
Calamity.live data shows a weather event with CalamityScore 46/100, near Mount Clemens (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.