This alert expired on 28 May 2026 at 09:00 UTC. It is kept here as a record.
No stronger detection stands among the 59 recorded within 20 km of this point since 19 March 2026 — 5 others scored the same. Another comparable one was recorded here earlier the same day. 7 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued May 28 at 2:26AM MDT until May 28 at 3:00AM MDT by NWS Great Falls MT
How we know
Confirmed by 4 independent sources, including NOAA.
Our own score for this event is 22 out of 100, at 71 % 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 | 71% |
| Coordinates | 47.9820, -112.1900 |
| Nearest City | Great Falls (85 km) |
| Impact Tier | minor |
| Timestamp | 2026-05-28T08:26:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.1516f72046d1303fad68da50ac3344fe503edeff.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Pondera, MT; Teton, MT |
| Headline | Severe Thunderstorm Warning issued May 28 at 2:26AM MDT until May 28 at 3:00AM MDT by NWS Great Falls MT |
| Expires | 2026-05-28T03:00:00-06:00 |
| SenderName | NWS Great Falls MT |
| HasExactCoords | true |
| Iem TypeSummary | G |
| Iem Magnitude | 59 |
| Iem Unit | MPH |
| Iem City | 5 ENE Choteau |
| Iem County | Teton |
| Iem State | MT |
| Iem Wfo | TFX |
| Iem Remark | Mesonet station GW6973 CHOTEAU. |
| MergedSources | [{"id":"iem_G_47.840_-112.080_1779954900000","source":"iem","severity":"low","severityValue":25,"timestamp":1779954900000,"latitude":47.84,"longitude":-112.08},{"id":"iem_G_47.840_-112.080_1779954600000","source":"iem","severity":"low","severityValue":25,"timestamp":1779954600000,"latitude":47.84,"longitude":-112.08},{"id":"iem_G_47.840_-112.080_1779955200000","source":"iem","severity":"low","severityValue":25,"timestamp":1779955200000,"latitude":47.84,"longitude":-112.08}] |
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.