Right now
The most recent data we hold from NOAA arrived 4 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 7 September 2026 at 04:00 UTC. It is kept here as a record.
It is one of only 4 we have recorded within 20 km of this point since 5 May 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 6 at 9:43PM MDT until September 6 at 10:00PM MDT by NWS Cheyenne WY
Nearby, since 5 May 2026
- September 7, 2026 · score 16 · 0.0 km
- June 21, 2026 · 13.0 km
- August 29, 2026 · 18.6 km
How we know
2 recorded sources include NOAA; independence is not established by this count.
Our own score for this event is 16 out of 100.
This is our versioned heuristic index, not source severity or a calibrated probability. Urban PEI does not count unique people.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 16 / 100 |
| Legacy data-support index | 0.66/1 |
| Coordinates | 42.5540, -104.8480 |
| Nearest City | Casper (125 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-09-07T03:43:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.c54dc57839e54641df9f06f16487f6b84ba342f1.001.1 |
Physical priority index · v4 (historical). Heuristic priority, not calibrated probability, predictive accuracy or damage. The legacy data-support index combines assigned source support and field availability. Urban PEI is distance-weighted and does not count unique people; zero does not establish that nobody is present. Model cards.
Source and revision timeline
Source: noaa. Occurrence: 2026-09-07T03:43:00.000Z.
First archived: 2026-09-07T03:50:13.926Z. Material modification: not recorded.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Converse, WY; Niobrara, WY; Platte, WY |
| Headline | Severe Thunderstorm Warning issued September 6 at 9:43PM MDT until September 6 at 10:00PM MDT by NWS Cheyenne WY |
| Expires | 2026-09-06T22:00:00-06:00 |
| SenderName | NWS Cheyenne WY |
| HasExactCoords | true |
| Spc ReportType | wind |
| Spc Speed | 73 |
| Spc Location | 8 S Sibley Peak |
| Spc County | Platte |
| Spc State | WY |
| Spc Comments | Mesonet station WY1 8.4 S Sibley Peak (WYDOT). (CYS) |
| MergedSources | [{"id":"spc_wind_42.32_-105.05_163","source":"spc","severity":"medium","severityValue":45,"timestamp":1788751080000,"latitude":42.32,"longitude":-105.05}] |
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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