This alert expired on 19 May 2026 at 21:30 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 — 27 others scored the same. Another comparable one was recorded here earlier the same day. 16 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued May 19 at 4:22PM EDT until May 19 at 5:30PM EDT by NWS Detroit/Pontiac MI
An estimated 2,360,599 people live within 50 km of this point.
Nearby, since 14 April 2026
- July 4, 2026 · score 52 · 2.8 km
- June 25, 2026 · score 52 · 5.1 km
- May 9, 2026 · score 52 · 6.0 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 out of 100, at 79 % 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) | 52 / 100 |
| Our confidence | 79% |
| Coordinates | 42.5601, -82.7692 |
| Nearest City | Mount Clemens (10 km) |
| Population Exposed | 2.4M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-19T20:22:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.65c386b5a8f22e66e9f1b60e9e10f2d8 |
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); St. Clair River; Lake St. Clair Open Lake (U.S. Portion); Port Sanilac to Port Huron MI |
| Headline | Special Marine Warning issued May 19 at 4:22PM EDT until May 19 at 5:30PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-05-19T17:30:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.65c386b5a8f22e66e9f1b60e9e10f2d877423044.001.1","noaa_urn:oid:2.49.0.1.840.0.0b11d3083d814d5892446b175b084116a6feb99f.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.
Calamity.live data shows a weather event with CalamityScore 52/100, near Mount Clemens (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.