Right now
The most recent data we hold from NOAA arrived 12 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
Nothing else has been detected within 20 km in the last 24 hours.
This alert expired on 21 May 2026 at 23:30 UTC. It is kept here as a record.
It is the 5th strongest of the 34 detections recorded within 20 km of this point since 6 May 2026. 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: Severe Thunderstorm Warning issued May 21 at 4:55PM MDT until May 21 at 5:30PM MDT by NWS Cheyenne WY
Nearby, since 6 May 2026
- May 21, 2026 · score 46 · 10.6 km
- June 3, 2026 · score 16 · 13.7 km
- May 9, 2026 · score 22 · 21.4 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 22 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 | Medium |
| Calamity Score (ours) | 22 / 100 |
| Our confidence | 59% |
| Coordinates | 40.4994, -103.6731 |
| Nearest City | Evans (87 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-21T22:55:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.6cd02de26e3542c31d9e434d4778a0e8 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Banner, NE; Kimball, NE; Eastern Arapahoe, CO; Washington, CO |
| Headline | Severe Thunderstorm Warning issued May 21 at 4:55PM 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:2.49.0.1.840.0.6cd02de26e3542c31d9e434d4778a0e831376da6.001.1","noaa_urn:oid:2.49.0.1.840.0.3a26ef5196077d47ec2e3a94b3435f966d1cf0bb.002.1"] |
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.
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