Right now
The most recent data we hold from NOAA arrived 6 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 03:04 UTC. It is kept here as a record.
It is the 6th strongest of the 12 detections recorded within 20 km of this point since 6 June 2026. Another comparable one was recorded here earlier the same day. 8 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued July 20 at 9:54PM CDT until July 20 at 10:00PM CDT by NWS Green Bay WI
Nearby, since 6 June 2026
- July 13, 2026 · score 22 · 1.3 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.
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 | 45.2770, -85.9798 |
| Nearest City | Traverse City (64 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-07-21T02:54:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.4846318e7bdf8241826731c9d88f39d1 |
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: 2026-07-21T02:54:00.000Z.
First archived: 2026-07-21T02:59:15.838Z. 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 | Lake Michigan from Rock Island Passage to Sturgeon Bay WI 5NM offshore to mid lake; 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; Grand Traverse Bay south of a line Grand Traverse Light to Norwood MI; Sleeping Bear Point to Grand Traverse Light MI; Point Betsie to Sleeping Bear Point MI; Lake Michigan from Charlevoix to Point Betsie MI 5NM Offshore to mid lake and 3 more areas |
| Headline | Special Marine Warning issued July 20 at 9:54PM CDT until July 20 at 10:00PM CDT by NWS Green Bay WI |
| Expires | 2026-07-20T22:04:00-05:00 |
| SenderName | NWS Green Bay WI |
| HasExactCoords | true |
| MergedCount | 6 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.4846318e7bdf8241826731c9d88f39d148882cfb.001.1","noaa_urn:oid:2.49.0.1.840.0.eeb961f55fa100a8165d9b91fcb6be59429d9b4b.001.1","noaa_urn:oid:2.49.0.1.840.0.d0d227ce5058c95c7fc653458ac23c7329cf5b72.001.1","noaa_urn:oid:2.49.0.1.840.0.fa4040643c18bb1e514915482ab256f956abcfff.001.1","noaa_urn:oid:2.49.0.1.840.0.1d165064e4f7f048c373baa711fba88496d71210.001.1","noaa_urn:oid:2.49.0.1.840.0.f546c0a6395c108a9604a6c3e4c36aab89fd2b99.001.1"] |
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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