This alert expired on 3 September 2026 at 20:30 UTC. It is kept here as a record.
No stronger detection stands among the 179 recorded within 20 km of this point since 17 March 2026 — 11 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Tornado Warning issued September 3 at 4:07PM EDT until September 3 at 4:30PM EDT by NWS Pittsburgh PA
An estimated 16,028 people live within 50 km of this point.
Nearby, since 17 March 2026
- September 3, 2026 · score 58 · 8.7 km
- September 2, 2026 · score 58 · 9.9 km
- July 21, 2026 · score 58 · 11.9 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 58 out of 100, at 81 % 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 | Critical |
| Calamity Score (ours) | 58 / 100 |
| Our confidence | 81% |
| Coordinates | 41.4400, -80.1743 |
| Nearest City | Hermitage (33 km) |
| Population Exposed | 16.0K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-03T20:07:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.427a99648a1e90fb4ad0a8811ab0fcc25f838207.001.1 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Mercer, PA |
| Headline | Tornado Warning issued September 3 at 4:07PM EDT until September 3 at 4:30PM EDT by NWS Pittsburgh PA |
| Expires | 2026-09-03T16:30:00-04:00 |
| SenderName | NWS Pittsburgh PA |
| 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 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 in this area?
Calamity.live data shows a weather event with CalamityScore 58/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.