Right now
The most recent data we hold from NOAA arrived 2 hours 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 01:30 UTC. It is kept here as a record.
It is the 6th strongest of the 7 detections recorded within 20 km of this point since 31 May 2026. 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 May 30 at 6:55PM MDT until May 30 at 7:30PM MDT by NWS Billings MT
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 16 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) | 16 / 100 |
| Our confidence | 60% |
| Coordinates | 45.8044, -105.8832 |
| Nearest City | Sheridan (140 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-31T00:55:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.4794bec574fe0093789eba7b294b4e99 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Custer, MT; Big Horn, MT; Rosebud, MT |
| Headline | Severe Thunderstorm Warning issued May 30 at 6:55PM MDT until May 30 at 7:30PM MDT by NWS Billings MT |
| Expires | 2026-05-30T19:30:00-06:00 |
| SenderName | NWS Billings MT |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.4794bec574fe0093789eba7b294b4e99d848fb97.001.1","noaa_urn:oid:2.49.0.1.840.0.4b362028fbd8ca804fdc5d005a0db9b235b21526.001.1"] |
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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