This alert expired on 3 September 2026 at 04:00 UTC. It is kept here as a record.
No stronger detection stands among the 52 recorded within 20 km of this point since 14 April 2026 — one other scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Special Marine Warning issued September 2 at 11:09PM EDT until September 3 at 12:00AM EDT by NWS Detroit/Pontiac MI
An estimated 2,784,206 people live within 50 km of this point.
Nearby, since 14 April 2026
- May 9, 2026 · score 52 · 2.4 km
- July 4, 2026 · score 52 · 5.4 km
- May 19, 2026 · score 52 · 6.5 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 58 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 | High |
| Calamity Score (ours) | 58 / 100 |
| Our confidence | 92% |
| Coordinates | 42.4942, -82.8117 |
| Nearest City | Saint Clair Shores (6 km) |
| Population Exposed | 2.8M within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-09-03T03:09:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.770dc6587d372185cc9edfe36a115f27e479ecba.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | St. Clair River; Detroit River; Lake St. Clair Open Lake (U.S. Portion) |
| Headline | Special Marine Warning issued September 2 at 11:09PM EDT until September 3 at 12:00AM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-09-03T00:00:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| Spc ReportType | hail |
| Spc Speed | 150 |
| Spc Location | Kimball |
| Spc County | St. Clair |
| Spc State | MI |
| Spc Comments | (DTX) |
| Iem TypeSummary | D |
| Iem City | 1 S South Park |
| Iem County | St. Clair |
| Iem State | MI |
| Iem Wfo | DTX |
| Iem Remark | Trees and wires downed along Peavey St. |
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 Saint Clair Shores?
Calamity.live data shows a weather event with CalamityScore 58/100, near Saint Clair Shores (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.