This alert expired on 5 September 2026 at 05:00 UTC. It is kept here as a record.
It is the 34th strongest of the 39 detections recorded within 20 km of this point since 10 March 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Special Marine Warning issued September 4 at 11:50PM CDT until September 5 at 12:00AM CDT by NWS Chicago IL
Nearby, since 10 March 2026
- September 5, 2026 · score 16 · 10.6 km
- May 18, 2026 · score 22 · 11.1 km
- March 10, 2026 · score 22 · 11.4 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 16 out of 100, at 62 % 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) | 16 / 100 |
| Our confidence | 62% |
| Coordinates | 42.2620, -86.9177 |
| Nearest City | Michigan City (61 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-05T04:50:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.a97fedcc596bb0e0ce58567243b85a7345e10a74.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5NM offshore to Mid Lake; Lake Michigan from Wilmette Harbor to Michigan City in 5NM offshore to Mid Lake; Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5NM offshore to Mid Lake; St Joseph to South Haven MI; Lake Michigan from St Joseph to South Haven MI 5NM offshore to Mid Lake |
| Headline | Special Marine Warning issued September 4 at 11:50PM CDT until September 5 at 12:00AM CDT by NWS Chicago IL |
| Expires | 2026-09-05T00:00:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.a97fedcc596bb0e0ce58567243b85a7345e10a74.001.1","noaa_urn:oid:2.49.0.1.840.0.a017ef82ffb0543bc2a73a2e9e44e0f5127dacef.001.1","noaa_urn:oid:2.49.0.1.840.0.ab73912da6de04090fa3f5b4d886e4dcdb5facc5.001.1"] |
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 16/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.