Right now
The most recent data we hold from NOAA arrived 11 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 31 May 2026 at 02:15 UTC. It is kept here as a record.
No stronger detection stands among the 14 recorded within 20 km of this point since 18 March 2026 — 4 others scored the same. The last comparable one was on 23 April 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 30 at 7:19PM MDT until May 30 at 8:15PM MDT by NWS Billings MT
Nearby, since 18 March 2026
- August 30, 2026 · score 22 · 14.4 km
- June 2, 2026 · score 22 · 20.9 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 60 % 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 | 60% |
| Coordinates | 45.5025, -106.0625 |
| Nearest City | Sheridan (105 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-31T01:19:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.6ebd3ef6e96bfc51758458a26c3cde52 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Custer, MT; Powder River, MT; Big Horn, MT; Rosebud, MT |
| Headline | Severe Thunderstorm Warning issued May 30 at 7:19PM MDT until May 30 at 8:15PM MDT by NWS Billings MT |
| Expires | 2026-05-30T20:15:00-06:00 |
| SenderName | NWS Billings MT |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.6ebd3ef6e96bfc51758458a26c3cde5246686d17.001.1","noaa_urn:oid:2.49.0.1.840.0.7692553609da34ec1e4229fc158fc4e3bdd6db96.001.1"] |
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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