This alert expired on 21 July 2026 at 13:30 UTC. It is kept here as a record.
No stronger detection stands among the 37 recorded within 20 km of this point since 16 March 2026 — one other scored the same. Another comparable one was recorded here earlier the same day. 2 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 21 at 9:09AM EDT until July 21 at 9:30AM EDT by NWS Cleveland OH
An estimated 129,550 people live within 50 km of this point.
Nearby, since 16 March 2026
- June 11, 2026 · score 37 · 15.8 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 43 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 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) | 43 / 100 |
| Our confidence | 81% |
| Coordinates | 42.1077, -79.6309 |
| Nearest City | Jamestown (32 km) |
| Population Exposed | 129.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-21T13:09:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.82afeb413d3c4a0da1b6bb1d4dcd819d |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Erie, PA; Chautauqua, NY |
| Headline | Severe Thunderstorm Warning issued July 21 at 9:09AM EDT until July 21 at 9:30AM EDT by NWS Cleveland OH |
| Expires | 2026-07-21T09:30:00-04:00 |
| SenderName | NWS Cleveland OH |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.82afeb413d3c4a0da1b6bb1d4dcd819d1f76d28b.001.1","noaa_urn:oid:2.49.0.1.840.0.472083a71b4c5e8c467daf6e71d7af4ecfbceb1c.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 in this area?
Calamity.live data shows a weather event with CalamityScore 43/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.