Right now
The most recent data we hold from NOAA arrived 4 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 18 May 2026 at 21:15 UTC. It is kept here as a record.
It is the 2nd strongest of the 20 detections recorded within 20 km of this point since 5 April 2026. Another comparable one was recorded here earlier the same day. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued May 18 at 4:17PM EDT until May 18 at 5:15PM EDT by NWS Detroit/Pontiac MI
Nearby, since 5 April 2026
- May 17, 2026 · score 46 · 25.6 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 22 out of 100, at 59 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v1. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 22 / 100 |
| Our confidence | 59% |
| Coordinates | 43.8401, -82.9603 |
| Nearest City | Bay City (80 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-18T20:17:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.e3d0705f3dd4bd44e638cbfbaaea61c9 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Outer Saginaw Bay SW of Alabaster to Port Austin MI to Inner Saginaw Bay; Port Austin to Harbor Beach MI; Lake Huron from Port Austin to Harbor Beach 5NM Off Shore to the US/Canadian border; Detroit River; Lake St. Clair Open Lake (U.S. Portion); Michigan Waters of Lake Erie from Detroit River to North Cape MI; Harbor Beach to Port Sanilac MI; Port Sanilac to Port Huron MI; Lake Huron from Harbor Beach to Port Sanilac 5NM Off Shore to US/Canadian border; Lake Huron from Port Sanilac to Port Huron 5NM Off Shore to US/Canadian border and 3 more areas |
| Headline | Special Marine Warning issued May 18 at 4:17PM EDT until May 18 at 5:15PM EDT by NWS Detroit/Pontiac MI |
| Expires | 2026-05-18T17:15:00-04:00 |
| SenderName | NWS Detroit/Pontiac MI |
| HasExactCoords | true |
| MergedCount | 6 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.e3d0705f3dd4bd44e638cbfbaaea61c95c8a6298.001.1","noaa_urn:oid:2.49.0.1.840.0.02f62cb9e61a46e52c1266d6c5b34c2e62069997.001.1","noaa_urn:oid:2.49.0.1.840.0.b4419f88efe363014b69a2083c31243e95622ff5.001.1","noaa_urn:oid:2.49.0.1.840.0.27fd31529cbcd0ba4272d7a66f8bddd5618b156d.001.1","noaa_urn:oid:2.49.0.1.840.0.47ca8d65d49d93ee271294bcaadfdbf52bfbb3a1.001.1","noaa_urn:oid:2.49.0.1.840.0.b98f0f5c6f9b8ca051c78c10444a1f192e7c5cce.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 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 in this area?
Calamity.live data shows a weather event with CalamityScore 22/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.