This alert expired on 18 May 2026 at 18:30 UTC. It is kept here as a record.
No stronger detection stands among the 36 recorded within 20 km of this point since 16 March 2026 — 10 others scored the same. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued May 18 at 1:51PM EDT until May 18 at 2:30PM EDT by NWS Grand Rapids MI
An estimated 33,742 people live within 50 km of this point.
Nearby, since 16 March 2026
- July 3, 2026 · score 34 · 9.1 km
- July 28, 2026 · score 34 · 19.8 km
- August 10, 2026 · score 22 · 21.0 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 34 out of 100, at 89 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
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) | 34 / 100 |
| Our confidence | 89% |
| Coordinates | 42.6056, -86.3856 |
| Nearest City | Holland (30 km) |
| Population Exposed | 33.7K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-18T17:51:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.36d696ffdd154933783d665675acd0b3f558396d.001.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | St Joseph to South Haven MI; South Haven to Holland MI; Holland to Grand Haven MI; Lake Michigan from Holland to Grand Haven MI 5NM offshore to Mid Lake; Lake Michigan from South Haven to Holland MI 5NM offshore to Mid lake; Lake Michigan from St Joseph to South Haven MI 5NM offshore to Mid Lake |
| Headline | Special Marine Warning issued May 18 at 1:51PM EDT until May 18 at 2:30PM EDT by NWS Grand Rapids MI |
| Expires | 2026-05-18T14:30:00-04:00 |
| SenderName | NWS Grand Rapids MI |
| HasExactCoords | true |
| Iem TypeSummary | G |
| Iem Magnitude | 63 |
| Iem Unit | MPH |
| Iem City | 1 N Benton Heights |
| Iem County | Berrien |
| Iem State | MI |
| Iem Wfo | IWX |
| Iem Remark | ASOS station KBEH Benton Harbor. |
| MergedSources | [{"id":"iem_G_42.400_-86.280_1779125760000","source":"iem","severity":"low","severityValue":25,"timestamp":1779125760000,"latitude":42.4,"longitude":-86.28},{"id":"iem_M_42.120_-86.490_1779124440000","source":"iem","severity":"low","severityValue":25,"timestamp":1779124440000,"latitude":42.12,"longitude":-86.49},{"id":"iem_M_42.110_-86.500_1779124440000","source":"iem","severity":"low","severityValue":25,"timestamp":1779124440000,"latitude":42.11,"longitude":-86.5},{"id":"iem_G_42.130_-86.420_1779125100000","source":"iem","severity":"low","severityValue":25,"timestamp":1779125100000,"latitude":42.13,"longitude":-86.42}] |
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 near Holland?
Calamity.live data shows a weather event with CalamityScore 34/100, near Holland (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.