This alert expired on 18 July 2026 at 22:00 UTC. It is kept here as a record.
It is one of only 2 we have recorded within 20 km of this point since 22 April 2026. The last comparable one was on 22 April 2026.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued July 18 at 3:47PM MDT until July 18 at 4:00PM MDT by NWS Great Falls MT
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 59 % 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 | 59% |
| Coordinates | 45.9300, -111.7150 |
| Nearest City | Bozeman (59 km) |
| Impact Tier | minor |
| Timestamp | 2026-07-18T21:47:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.8c5bc2fc7a687a9c6fcf4675594f653eb1e24553.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Broadwater, MT; Gallatin, MT; Jefferson, MT; Madison, MT |
| Headline | Severe Thunderstorm Warning issued July 18 at 3:47PM 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 |
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 22/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.