This alert expired on 10 May 2026 at 05:30 UTC. It is kept here as a record.
No stronger detection stands among the 86 recorded within 20 km of this point since 11 March 2026 — 27 others scored the same. Another comparable one was recorded here earlier the same day. 7 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued May 10 at 12:46AM EDT until May 10 at 1:30AM EDT by NWS Cleveland OH
An estimated 1,559,725 people live within 50 km of this point.
Nearby, since 11 March 2026
- June 25, 2026 · score 46 · 3.5 km
- May 10, 2026 · score 52 · 3.9 km
- June 25, 2026 · score 52 · 4.6 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 out of 100, at 81 % 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 | 81% |
| Coordinates | 41.5117, -81.8525 |
| Nearest City | Rocky River (4 km) |
| Population Exposed | 1.6M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-10T04:46:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.932e33adf89c8a561da27ac897e47470b05058b7.002.1 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Vermilion to Avon Point OH; Avon Point to Willowick OH; Avon Point to Willowick OH beyond 5 nm off shoreline to US-Canadian border |
| Headline | Special Marine Warning issued May 10 at 12:46AM EDT until May 10 at 1:30AM EDT by NWS Cleveland OH |
| Expires | 2026-05-10T01:30:00-04:00 |
| SenderName | NWS Cleveland OH |
| HasExactCoords | true |
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 Rocky River (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.