Right now
The most recent data we hold from NOAA arrived 5 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 21 July 2026 at 03:45 UTC. It is kept here as a record.
It is the 2nd strongest of the 8 detections recorded within 20 km of this point since 3 April 2026. The last comparable one was on 13 July 2026. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued July 20 at 9:48PM EDT until July 20 at 11:45PM EDT by NWS Gaylord MI
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.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
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) | 16 / 100 |
| Legacy data-support index | 0.60/1 |
| Coordinates | 45.5455, -85.7335 |
| Nearest City | Traverse City (88 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-07-21T01:48:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.20a9468add5937b57fce15bf3b02ed2e |
Physical priority index · v1. Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-07-21T01:48:00.000Z.
First archived: 2026-07-21T01:50:51.141Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | St Ignace to False Detour Channel; 5NM East of Mackinac Bridge to Presque Isle Light MI including Bois Blanc Island; Lake Huron from 5NM east of Mackinac Bridge to Presque Isle Lt to the US/Canadian border beyond 5 NM from shore; Straits of Mackinac within 5 nm of Mackinac Bridge including Mackinac Island; Seul Choix Point to 5NM West of Mackinac Bridge; Norwood MI to 5NM West of Mackinac Bridge including Little Traverse Bay; Sleeping Bear Point to Grand Traverse Light MI; Lake Michigan South of a line from Seul Choix Point to the Mackinac Bridge and North of a line from Charlevoix MI to South Fox Island 5NM offshore; Lake Michigan from Charlevoix to Point Betsie MI 5NM Offshore to mid lake; Rock Island Passage to Sturgeon Bay WI; Lake Michigan from Rock Island Passage to Sturgeon Bay WI 5NM offshore to mid lake and 1 more areas |
| Headline | Special Marine Warning issued July 20 at 9:48PM EDT until July 20 at 11:45PM EDT by NWS Gaylord MI |
| Expires | 2026-07-20T23:45:00-04:00 |
| SenderName | NWS Gaylord MI |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.20a9468add5937b57fce15bf3b02ed2e3b381bd7.001.1","noaa_urn:oid:2.49.0.1.840.0.b6d52556f0de4a923e44b8a9bd793a81c3ebcb1e.001.1","noaa_urn:oid:2.49.0.1.840.0.688e2eefaa927a3d9493166e2bddcdda35822e7a.001.1","noaa_urn:oid:2.49.0.1.840.0.1a74909b655c24370b432b414f751f2da81e626b.002.1"] |
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.
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