This alert expired on 2 September 2026 at 11:30 UTC. It is kept here as a record.
It is the 22nd strongest of the 22 detections recorded within 20 km of this point since 17 May 2026. The last comparable one was on 27 July 2026.
What the source measured
NOAA reported: Special Marine Warning issued September 2 at 6:20AM CDT until September 2 at 6:30AM CDT by NWS Green Bay WI
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 61 % 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 | 61% |
| Coordinates | 44.3252, -86.7941 |
| Nearest City | Manitowoc (74 km) |
| Impact Tier | minor |
| Timestamp | 2026-09-02T11:20:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.38978a07dc5631d41da4dd7f041722d4bd78e1c1.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Sturgeon Bay to Two Rivers WI; Two Rivers to Sheboygan WI; Lake Michigan from Sturgeon Bay to Two Rivers WI 5NM offshore to Mid Lake; Lake Michigan from Two Rivers to Sheboygan WI 5NM offshore to Mid Lake; Sleeping Bear Point to Grand Traverse Light MI; Point Betsie to Sleeping Bear Point MI; Manistee to Point Betsie MI; Lake Michigan from Charlevoix to Point Betsie MI 5NM Offshore to mid lake; Lake Michigan from Point Betsie to Manistee MI 5NM offshore to Mid Lake; Pentwater to Manistee MI; Lake Michigan from Pentwater to Manistee MI 5NM offshore to Mid Lake |
| Headline | Special Marine Warning issued September 2 at 6:20AM CDT until September 2 at 6:30AM CDT by NWS Green Bay WI |
| Expires | 2026-09-02T06:30:00-05:00 |
| SenderName | NWS Green Bay WI |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.38978a07dc5631d41da4dd7f041722d4bd78e1c1.001.1","noaa_urn:oid:2.49.0.1.840.0.8e0b34ae6dc6f2ceb44a6f1c10a333b134792750.001.1","noaa_urn:oid:2.49.0.1.840.0.78f7b5d4ab65716184abdfb576959fead1c65783.001.1"] |
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.