This alert expired on 21 May 2026 at 23:30 UTC. It is kept here as a record.
No stronger detection stands among the 61 recorded within 20 km of this point since 21 May 2026 — 15 others scored the same. Another comparable one was recorded here earlier the same day. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued May 21 at 5:04PM MDT until May 21 at 5:30PM MDT by NWS Cheyenne WY
Nearby, since 21 May 2026
- July 4, 2026 · score 46 · 19.3 km
- June 25, 2026 · score 46 · 19.9 km
- July 8, 2026 · score 22 · 21.9 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 46 out of 100, at 59 % 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 | Critical |
| Calamity Score (ours) | 46 / 100 |
| Our confidence | 59% |
| Coordinates | 40.4267, -103.5917 |
| Nearest City | Evans (93 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-21T23:04:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Tornado Warning_noaa_urn:oid:2.49.0.1.840.0.897665d9084fac75e593ba7f1c5f7642 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Kimball, NE; Lincoln, CO; Washington, CO |
| Headline | Tornado Warning issued May 21 at 5:04PM MDT until May 21 at 5:30PM MDT by NWS Cheyenne WY |
| Expires | 2026-05-21T17:30:00-06:00 |
| SenderName | NWS Cheyenne WY |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.897665d9084fac75e593ba7f1c5f76425d6764e0.001.1","noaa_urn:oid:2.49.0.1.840.0.7d52deffc584aa668a2e3f595037d2594f40293d.001.1"] |
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 46/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.