Right now
The most recent data we hold from NOAA arrived 10 minutes ago, and this point is not in it. We record detections, not passes: an absence is not proof that nothing is there.
4 other detections within 20 km in the last 24 hours, the nearest 12 km from here.
This alert expired on 19 September 2026 at 03:15 UTC. It is kept here as a record.
It is the 16th strongest of the 20 detections recorded within 20 km of this point since 21 May 2026. Another comparable one was recorded here earlier the same day. 3 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 18 at 8:22PM MDT until September 18 at 9:15PM MDT by NWS Cheyenne WY
Nearby, since 21 May 2026
- September 19, 2026 · score 16 · 11.7 km
- August 9, 2026 · score 22 · 18.7 km
How we know
3 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 v5. 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 | 0.71/1 |
| Coordinates | 42.2027, -103.6942 |
| Nearest City | Cheyenne (151 km) |
| Urban exposure index (PEI) | 0 within 50 km |
| Impact Tier | minor |
| Timestamp | 2026-09-19T02:22:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.138e32a977992b96880e28d9dd6cdcd0e5234054.001.1 |
Physical priority index · v5. 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: 2026-09-19T02:22:00.000Z.
First archived: 2026-09-19T02:29:08.892Z. Material modification: 2026-09-19T02:34:31.897Z.
Retained revisions are prospective; earlier versions may be unavailable. No revision entry does not prove that a record never changed.
2026-09-19T02:34:31.897Z · data_change
Index 16 → 16; severity medium → medium; version 5 → 5.
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Dawes, NE; Sioux, NE; Banner, NE; Scotts Bluff, NE; Sioux, NE |
| Headline | Severe Thunderstorm Warning issued September 18 at 8:22PM MDT until September 18 at 9:15PM MDT by NWS Cheyenne WY |
| Expires | 2026-09-18T21:15:00-06:00 |
| SenderName | NWS Cheyenne WY |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.138e32a977992b96880e28d9dd6cdcd0e5234054.001.1","noaa_urn:oid:2.49.0.1.840.0.a6cec8a47a6c55e449211aa2f192d0c067fb4aed.002.1"] |
| Spc ReportType | wind |
| Spc Speed | 62 |
| Spc Location | 2 SW Harrison |
| Spc County | Sioux |
| Spc State | NE |
| Spc Comments | Personal weather station. (CYS) |
| Iem TypeSummary | G |
| Iem Magnitude | 62 |
| Iem Unit | MPH |
| Iem City | 2 SW Harrison |
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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