This alert expired on 23 June 2026 at 00:30 UTC. It is kept here as a record.
No stronger detection stands among the 26 recorded within 20 km of this point since 3 May 2026 — 7 others scored the same. Another comparable one was recorded here earlier the same day. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued June 22 at 5:50PM MDT until June 22 at 6:30PM MDT by NWS Cheyenne WY
How we know
Confirmed by 8 independent sources, including NOAA.
Our own score for this event is 22 out of 100, at 69 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 22 / 100 |
| Our confidence | 69% |
| Coordinates | 42.7883, -104.1233 |
| Nearest City | Rapid City (161 km) |
| Impact Tier | minor |
| Timestamp | 2026-06-22T23:50:00.000Z |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Sioux, NE; Niobrara, WY |
| Headline | Severe Thunderstorm Warning issued June 22 at 5:50PM MDT until June 22 at 6:30PM MDT by NWS Cheyenne WY |
| Expires | 2026-06-22T18:30:00-06:00 |
| SenderName | NWS Cheyenne WY |
| HasExactCoords | true |
| Iem TypeSummary | H |
| Iem Magnitude | 1.5 |
| Iem Unit | Inch |
| Iem City | 8 ESE Jay Em |
| Iem County | Goshen |
| Iem State | WY |
| Iem Wfo | CYS |
| Iem Remark | Reports of ping-pong ball sized hail covering the ground in the wake of the storm. |
| MergedSources | [{"id":"iem_H_42.810_-104.090_1782161220000","source":"iem","severity":"low","severityValue":25,"timestamp":1782161220000,"latitude":42.81,"longitude":-104.09},{"id":"iem_C_42.780_-104.640_1782162660000","source":"iem","severity":"low","severityValue":25,"timestamp":1782162660000,"latitude":42.78,"longitude":-104.64},{"id":"iem_H_42.760_-104.530_1782163080000","source":"iem","severity":"low","severityValue":25,"timestamp":1782163080000,"latitude":42.76,"longitude":-104.53},{"id":"iem_H_42.230_-104.050_1782169260000","source":"iem","severity":"low","severityValue":25,"timestamp":1782169260000,"latitude":42.23,"longitude":-104.05},{"id":"iem_H_42.500_-104.200_1782167760000","source":"iem","severity":"low","severityValue":25,"timestamp":1782167760000,"latitude":42.5,"longitude":-104.2},{"id":"iem_H_42.650_-104.390_1782164820000","source":"iem","severity":"low","severityValue":25,"timestamp":1782164820000,"latitude":42.65,"longitude":-104.39},{"id":"iem_H_42.410_-104.210_1782166620000","source":"iem","severity":"low","severityValue":25,"timestamp":1782166620000,"latitude":42.41,"longitude":-104.21}] |
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 10 February 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.
Calamity.live data shows a weather event with CalamityScore 22/100, near Rapid City (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 191 scientific monitoring sources.