This alert expired on 18 July 2026 at 22:00 UTC. It is kept here as a record.
No stronger detection stands among the 6 recorded within 20 km of this point since 25 April 2026 — 3 others scored the same. 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 July 18 at 2:53PM MDT until July 18 at 4:00PM MDT by NWS Great Falls MT
An estimated 34,190 people live within 50 km of this point.
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 34 out of 100, at 79 % 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) | 34 / 100 |
| Our confidence | 79% |
| Coordinates | 45.7875, -112.1725 |
| Nearest City | Butte (36 km) |
| Population Exposed | 34.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-07-18T20:53:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.9dbd01b9d7fb0add710a78428b791132 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Broadwater, MT; Gallatin, MT; Jefferson, MT; Madison, MT; Beaverhead, MT; Jefferson, MT; Madison, MT |
| Headline | Severe Thunderstorm Warning issued July 18 at 2:53PM MDT until July 18 at 4:00PM MDT by NWS Great Falls MT |
| Expires | 2026-07-18T16:00:00-06:00 |
| SenderName | NWS Great Falls MT |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.9dbd01b9d7fb0add710a78428b791132044ee777.001.1","noaa_urn:oid:2.49.0.1.840.0.6566608533bc4ff7b74093af3720c046e4f6d264.001.1"] |
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.
Want to know when something happens in this area?
Calamity.live data shows a weather event with CalamityScore 34/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.