This alert expired on 2 September 2026 at 23:00 UTC. It is kept here as a record.
It is the 4th strongest of the 16 detections recorded within 20 km of this point since 18 March 2026. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued September 2 at 3:59PM MDT until September 2 at 5:00PM MDT by NWS Great Falls MT
An estimated 59,638 people live within 50 km of this point.
Nearby, since 18 March 2026
- August 27, 2026 · score 39 · 12.5 km
- May 13, 2026 · score 39 · 15.5 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 32 out of 100, at 90 % 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) | 32 / 100 |
| Our confidence | 90% |
| Coordinates | 47.2401, -111.1598 |
| Nearest City | Great Falls (31 km) |
| Population Exposed | 59.6K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-09-02T21:59:00.000Z |
| Source | https://api.weather.gov/alerts/urn%3Aoid%3A2.49.0.1.840.0.edbe67c3797b5e30a9c4731714d279e5debd3181.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Cascade, MT; Chouteau, MT; Lewis and Clark, MT; Pondera, MT; Teton, MT; Meagher, MT; Cascade, MT; Chouteau, MT; Hill, MT; Judith Basin, MT; Liberty, MT; Pondera, MT; Teton, MT; Toole, MT |
| Headline | Severe Thunderstorm Warning issued September 2 at 3:59PM MDT until September 2 at 5:00PM MDT by NWS Great Falls MT |
| Expires | 2026-09-02T17:00:00-06:00 |
| SenderName | NWS Great Falls MT |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.edbe67c3797b5e30a9c4731714d279e5debd3181.001.1","noaa_urn:oid:2.49.0.1.840.0.b779ff0a24f07d475ab7b0063c367d07eb0130b8.002.1","noaa_urn:oid:2.49.0.1.840.0.e5494c6947a2888b53ed9241a6ef6a2caf3765ca.001.1"] |
| Spc ReportType | wind |
| Spc Speed | 63 |
| Spc Location | 7 ENE Power |
| Spc County | Teton |
| Spc State | MT |
| Spc Comments | AWOS station K1JM 6 ENE Power. (TFX) |
| Iem TypeSummary | G |
| Iem Magnitude | 67 |
| Iem Unit | MPH |
| Iem City | 1 ESE Malmstrom Afb |
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 32/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.