This alert expired on 19 May 2026 at 20:45 UTC. It is kept here as a record.
It is the 2nd strongest of the 22 detections recorded within 20 km of this point since 4 April 2026. Another comparable one was recorded here earlier the same day. 4 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued May 19 at 3:42PM EDT until May 19 at 4:45PM EDT by NWS Detroit/Pontiac MI
An estimated 291,707 people live within 50 km of this point.
Nearby, since 4 April 2026
- June 25, 2026 · score 43 · 8.1 km
- July 21, 2026 · score 37 · 8.8 km
- July 21, 2026 · score 43 · 9.5 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 out of 100, at 80 % 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) | 43 / 100 |
| Our confidence | 80% |
| Coordinates | 42.9401, -82.5582 |
| Nearest City | Port Huron (12 km) |
| Population Exposed | 291.7K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-19T19:42:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.ce3f108eb1954e9b23bbdcd76b413dbe |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Port Sanilac to Port Huron MI; Lake Huron from Port Sanilac to Port Huron 5NM Off Shore to US/Canadian border; 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 3:42PM EDT until May 19 at 4:45PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-05-19T16:45:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.ce3f108eb1954e9b23bbdcd76b413dbe2159e81b.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.
Want to know when something happens near Port Huron?
Calamity.live data shows a weather event with CalamityScore 43/100, near Port Huron (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 187 scientific monitoring sources.