Right now
The most recent data we hold from NOAA arrived 1 minute 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 June 2026 at 00:15 UTC. It is kept here as a record.
No stronger detection stands among the 14 recorded within 20 km of this point since 30 March 2026 — one other 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 20 at 5:36PM MDT until June 20 at 6:15PM MDT by NWS Rapid City SD
An estimated 60,285 people live within 50 km of this point.
How we know
Confirmed by 21 independent sources, including NOAA.
Our own score for this event is 39 out of 100, at 89 % 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) | 39 / 100 |
| Our confidence | 89% |
| Coordinates | 42.9865, -105.7581 |
| Nearest City | Casper (47 km) |
| Population Exposed | 60.3K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-20T23:36:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.1f8e5fb1180391ac84d7a25c94380a03 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Campbell, WY; Crook, WY; Weston, WY; Johnson, WY; Converse, WY; Goshen, WY; Niobrara, WY; Platte, WY and 2 more areas |
| Headline | Severe Thunderstorm Warning issued June 20 at 5:36PM MDT until June 20 at 6:15PM MDT by NWS Rapid City SD |
| Expires | 2026-06-20T18:15:00-06:00 |
| SenderName | NWS Rapid City SD |
| HasExactCoords | true |
| MergedCount | 5 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.1f8e5fb1180391ac84d7a25c94380a033945a058.001.1","noaa_urn:oid:2.49.0.1.840.0.b3330715dd92dc34b1e4749a498cbea6ad8ded07.001.1","noaa_urn:oid:2.49.0.1.840.0.7e87dc642a16d1648230640400b89902045e6a92.001.1","noaa_urn:oid:2.49.0.1.840.0.4b5bddc7ae61969a212d04d1f14a8afacc42af90.001.1","noaa_urn:oid:2.49.0.1.840.0.e3c36df93b62813c9d73439a678c261bfd4fa033.001.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 67 |
| Iem Unit | MPH |
| Iem City | 8 NNW Glendo |
| Iem County | Platte |
| Iem State | WY |
| Iem Wfo | CYS |
| Iem Remark | Mesonet station WY56 I25 Us26 Us87 - Platte Converse. |
| MergedSources | [{"id":"iem_G_43.120_-106.340_1781993160000","source":"iem","severity":"low","severityValue":25,"timestamp":1781993160000,"latitude":43.12,"longitude":-106.34},{"id":"iem_G_42.800_-105.380_1781996340000","source":"iem","severity":"low","severityValue":25,"timestamp":1781996340000,"latitude":42.8,"longitude":-105.38},{"id":"iem_G_43.000_-105.310_1781997000000","source":"iem","severity":"low","severityValue":25,"timestamp":1781997000000,"latitude":43,"longitude":-105.31},{"id":"iem_G_43.120_-106.340_1781992560000","source":"iem","severity":"low","severityValue":25,"timestamp":1781992560000,"latitude":43.12,"longitude":-106.34},{"id":"iem_G_43.180_-106.340_1781992200000","source":"iem","severity":"low","severityValue":25,"timestamp":1781992200000,"latitude":43.18,"longitude":-106.34},{"id":"iem_G_42.770_-106.250_1781992200000","source":"iem","severity":"low","severityValue":25,"timestamp":1781992200000,"latitude":42.77,"longitude":-106.25},{"id":"iem_G_42.790_-106.310_1781992200000","source":"iem","severity":"low","severityValue":25,"timestamp":1781992200000,"latitude":42.79,"longitude":-106.31},{"id":"iem_G_43.510_-105.420_1781995380000","source":"iem","severity":"low","severityValue":25,"timestamp":1781995380000,"latitude":43.51,"longitude":-105.42},{"id":"iem_G_43.410_-105.890_1781993580000","source":"iem","severity":"low","severityValue":25,"timestamp":1781993580000,"latitude":43.41,"longitude":-105.89},{"id":"iem_G_43.260_-105.860_1781994060000","source":"iem","severity":"low","severityValue":25,"timestamp":1781994060000,"latitude":43.26,"longitude":-105.86},{"id":"iem_G_42.720_-105.490_1781995140000","source":"iem","severity":"low","severityValue":25,"timestamp":1781995140000,"latitude":42.72,"longitude":-105.49},{"id":"iem_G_42.950_-106.500_1781991900000","source":"iem","severity":"low","severityValue":25,"timestamp":1781991900000,"latitude":42.95,"longitude":-106.5},{"id":"iem_G_42.720_-105.490_1781995680000","source":"iem","severity":"low","severityValue":25,"timestamp":1781995680000,"latitude":42.72,"longitude":-105.49},{"id":"iem_G_42.720_-105.490_1781995080000","source":"iem","severity":"low","severityValue":25,"timestamp":1781995080000,"latitude":42.72,"longitude":-105.49},{"id":"iem_G_43.460_-105.390_1781995800000","source":"iem","severity":"low","severityValue":25,"timestamp":1781995800000,"latitude":43.46,"longitude":-105.39},{"id":"iem_G_42.720_-106.060_1781992800000","source":"iem","severity":"low","severityValue":25,"timestamp":1781992800000,"latitude":42.72,"longitude":-106.06},{"id":"iem_G_42.600_-105.100_1781996760000","source":"iem","severity":"low","severityValue":25,"timestamp":1781996760000,"latitude":42.6,"longitude":-105.1},{"id":"iem_G_42.840_-106.200_1781993760000","source":"iem","severity":"low","severityValue":25,"timestamp":1781993760000,"latitude":42.84,"longitude":-106.2},{"id":"iem_G_42.900_-106.470_1781991660000","source":"iem","severity":"low","severityValue":25,"timestamp":1781991660000,"latitude":42.9,"longitude":-106.47},{"id":"iem_G_42.600_-105.100_1781997360000","source":"iem","severity":"low","severityValue":25,"timestamp":1781997360000,"latitude":42.6,"longitude":-105.1}] |
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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