This alert expired on 4 September 2026 at 20:00 UTC. It is kept here as a record.
It is the 45th strongest of the 138 detections recorded within 20 km of this point since 12 March 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 4 at 3:46PM EDT until September 4 at 4:00PM EDT by NWS Wilmington OH
An estimated 657,591 people live within 50 km of this point.
Nearby, since 12 March 2026
- August 2, 2026 · score 72 · 0.8 km
- May 19, 2026 · score 48 · 7.0 km
- September 4, 2026 · score 41 · 7.5 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 41 out of 100, at 80 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 41 / 100 |
| Our confidence | 80% |
| Coordinates | 39.8568, -84.2835 |
| Nearest City | Trotwood (7 km) |
| Population Exposed | 657.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-04T19:46:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.e8a1653fcdde0d9d2b90a30d0f55a5e9b490fade.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Darke, OH; Miami, OH; Montgomery, OH; Preble, OH; Montgomery, OH; Clark, OH; Greene, OH; Miami, OH; Montgomery, OH |
| Headline | Severe Thunderstorm Warning issued September 4 at 3:46PM EDT until September 4 at 4:00PM EDT by NWS Wilmington OH |
| Expires | 2026-09-04T16:00:00-04:00 |
| SenderName | NWS Wilmington OH |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.e8a1653fcdde0d9d2b90a30d0f55a5e9b490fade.001.1","noaa_urn:oid:2.49.0.1.840.0.133e802b0e3c9ce72e80687527cb7152b3d603da.001.1","noaa_urn:oid:2.49.0.1.840.0.a9490adb921f4aa0bd7824d26d18210d53d8c1bc.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.
Want to know when something happens near Trotwood?
Calamity.live data shows a weather event with CalamityScore 41/100, near Trotwood (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.