Right now
The most recent data we hold from NOAA arrived 14 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 00:30 UTC. It is kept here as a record.
It is the 3rd strongest of the 14 detections recorded within 20 km of this point since 16 March 2026. The last comparable one was on 20 July 2026. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued July 20 at 8:03PM EDT until July 20 at 8:30PM EDT by NWS Marquette 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 | 45.5990, -86.5056 |
| Nearest City | Traverse City (116 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-07-21T00:03:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.94977fb0385dc9874396bc575740d5bb |
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: 2026-07-21T00:03:00.000Z.
First archived: 2026-07-21T00:05:12.444Z. 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 | Green Bay North of line from Cedar River MI to Rock Island Passage; Seul Choix Point to 5NM West of Mackinac Bridge; 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; Green Bay south of line from Cedar River to Rock Island Passage and north of a line from Oconto WI to Little Sturgeon Bay WI; 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 8:03PM EDT until July 20 at 8:30PM EDT by NWS Marquette MI |
| Expires | 2026-07-20T20:30:00-04:00 |
| SenderName | NWS Marquette MI |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.94977fb0385dc9874396bc575740d5bbe1bf8300.001.1","noaa_urn:oid:2.49.0.1.840.0.8e0a69b3e8da624b4d8454ef03bc2cb81948be3d.001.1","noaa_urn:oid:2.49.0.1.840.0.1f6bad1469a516aeb85cce3bf92320ecf4187f09.001.1","noaa_urn:oid:2.49.0.1.840.0.7a9e9a988d8f15035e19c16d59ba213202e20f34.001.1"] |
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.
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