This alert expired on 18 May 2026 at 23:45 UTC. It is kept here as a record.
No stronger detection stands among the 50 recorded within 20 km of this point since 4 April 2026 — 22 others scored the same. Another comparable one was recorded here earlier the same day. 14 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued May 18 at 5:48PM EDT until May 18 at 7:45PM EDT by NWS Cleveland OH
An estimated 2,762,150 people live within 50 km of this point.
Nearby, since 4 April 2026
- May 19, 2026 · score 52 · 10.3 km
- May 19, 2026 · score 52 · 13.5 km
- May 19, 2026 · score 52 · 14.3 km
How we know
Confirmed by 8 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 89 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 52 / 100 |
| Our confidence | 89% |
| Coordinates | 42.6452, -82.9533 |
| Nearest City | Clinton Township (7 km) |
| Population Exposed | 2.8M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T21:48:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.1e577237abf9bb50e43f5f264f1e4d94 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Reno Beach to The Islands OH; The Islands to Vermilion OH; Reno Beach to The Islands OH beyond 5NM off shoreline to US-Canadian border; The Islands to Vermilion OH beyond 5 nm off shoreline to US-Canadian border; Maumee Bay to Reno Beach OH; Reno Beach to The Islands OH; Detroit River Lt. to Maumee Bay OH to Reno Beach OH beyond 5NM offshoreline to US-Canadian border; Reno Beach to The Islands OH beyond 5NM off shoreline to US-Canadian border; St. Clair River; Port Austin to Harbor Beach MI; Harbor Beach to Port Sanilac MI; Port Sanilac to Port Huron MI; Lake Huron from Port Austin to Harbor Beach 5NM Off Shore to the US/Canadian border; Lake Huron from Harbor Beach to Port Sanilac 5NM Off Shore to US/Canadian border; Lake Huron from Port Sanilac to Port Huron 5NM Off Shore to US/Canadian border and 2 more areas |
| Headline | Special Marine Warning issued May 18 at 5:48PM EDT until May 18 at 7:45PM EDT by NWS Cleveland OH |
| Expires | 2026-05-18T19:45:00-04:00 |
| SenderName | NWS Cleveland OH |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.1e577237abf9bb50e43f5f264f1e4d94fb4c4ba9.001.1","noaa_urn:oid:2.49.0.1.840.0.6a211a7d492e4ed53dc7457b0bc8e87a0548812e.001.1","noaa_urn:oid:2.49.0.1.840.0.4e9315d6435fcbfd0aa25b81933a05101b60d712.001.1","noaa_urn:oid:2.49.0.1.840.0.0a4ae23467643d6ed9082c6ac049a0f56dea81d5.001.1","noaa_urn:oid:2.49.0.1.840.0.fa95505119af60681c8140b8d2955505010e4338.001.1"] |
| Iem TypeSummary | D |
| Iem City | 1 NW Rochester Hills |
| Iem County | Oakland |
| Iem State | MI |
| Iem Wfo | DTX |
| Iem Remark | Report of large tree limb down on house causing damage to roofing |
| Google News RssFeed | weather |
| Google News SourceName | ClickOnDetroit | WDIV Local 4 |
| MergedSources | [{"id":"iem_G_42.660_-83.410_1779137100000","source":"iem","severity":"low","severityValue":25,"timestamp":1779137100000,"latitude":42.66,"longitude":-83.41},{"id":"iem_D_42.660_-83.170_1779132240000","source":"iem","severity":"low","severityValue":25,"timestamp":1779132240000,"latitude":42.66,"longitude":-83.17},{"id":"gnews_weather_494202_120","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779130324000,"latitude":42.33,"longitude":-83.05},{"id":"gnews_weather_494203_121","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779131397000,"latitude":42.33,"longitude":-83.05},{"id":"gnews_weather_494204_125","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779134883000,"latitude":42.33,"longitude":-83.05},{"id":"gnews_weather_494203_131","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779133500000,"latitude":42.33,"longitude":-83.05},{"id":"gnews_weather_494201_143","source":"google_news","severity":"medium","severityValue":40,"timestamp":1779124179000,"latitude":42.33,"longitude":-83.05}] |
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 10 February 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.
Calamity.live data shows a weather event with CalamityScore 52/100, near Clinton Township (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.