This alert expired on 2 September 2026 at 20:30 UTC. It is kept here as a record.
No stronger detection stands among the 6 recorded within 20 km of this point since 7 April 2026 — one other scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 2 at 2:02PM MDT until September 2 at 2:30PM MDT by NWS Great Falls MT
An estimated 34,190 people live within 50 km of this point.
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 28 out of 100, at 91 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Computed under scoring rules v4. Rows carrying other versions were judged by different rules and are not directly comparable.
Event Data
| Type | Severe Weather |
| Severity | Medium |
| Calamity Score (ours) | 28 / 100 |
| Our confidence | 91% |
| Coordinates | 46.4120, -112.6820 |
| Nearest City | Butte (47 km) |
| Population Exposed | 34.2K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-02T20:02:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.8b387f3e490722ef8853cb01975f9d1bf881f78d.002.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Jefferson, MT; Madison, MT; Powell, MT |
| Headline | Severe Thunderstorm Warning issued September 2 at 2:02PM MDT until September 2 at 2:30PM MDT by NWS Great Falls MT |
| Expires | 2026-09-02T14:30:00-06:00 |
| SenderName | NWS Great Falls MT |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.8b387f3e490722ef8853cb01975f9d1bf881f78d.002.1","noaa_urn:oid:2.49.0.1.840.0.facee105b02a99ede5ab8f0c5bbae0a7e5927663.001.1"] |
| Spc ReportType | wind |
| Spc Speed | 58 |
| Spc Location | 4 NNW Opportunity |
| Spc County | Deer Lodge |
| Spc State | MT |
| Spc Comments | Anaconda Bowman Field Airport AWOS K3U3 reported southwest wind sustained at 40 mph with gusts to 58 mph. At 1331 it reported a sustained wind of 44 mph. So far there h (MSO) |
| Iem TypeSummary | G |
| Iem Magnitude | 58 |
| Iem Unit | MPH |
| Iem City | 4 NNW Opportunity |
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 28/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.