This alert expired on 11 August 2026 at 14:04 UTC. It is kept here as a record.
No stronger detection stands among the 52 recorded within 20 km of this point since 15 March 2026 — 3 others scored the same. Another comparable one was recorded here earlier the same day. 16 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued August 11 at 9:55AM EDT until August 11 at 10:00AM EDT by NWS Wilmington OH
An estimated 1,335,280 people live within 50 km of this point.
Nearby, since 15 March 2026
- May 20, 2026 · score 52 · 1.6 km
- May 20, 2026 · score 52 · 4.5 km
- August 16, 2026 · score 52 · 5.1 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 76 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 | critical |
| Calamity Score (ours) | 76 / 100 |
| Our confidence | 81% |
| Coordinates | 39.9288, -83.3225 |
| Nearest City | Hilliard (18 km) |
| Population Exposed | 1.3M within 50 km |
| Impact Tier | catastrophic |
| Timestamp | 2026-08-11T13:55:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.f1dfc91594e773ddd36cc089360b0a5b3fd49a08.001.1 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Madison, OH |
| Headline | Tornado Warning issued August 11 at 9:55AM EDT until August 11 at 10:00AM EDT by NWS Wilmington OH |
| Expires | 2026-08-11T10:04:00-04:00 |
| SenderName | NWS Wilmington OH |
| HasExactCoords | true |
Safety Information
If a tornado warning is issued: go to a basement or an interior room on the lowest floor, away from windows. A vehicle and a mobile home are not shelter. Cover your head and neck. Wait for the official all-clear before going outside, and watch for downed power lines and gas leaks afterwards.
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 76/100, near Hilliard (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.