This alert expired on 27 May 2026 at 01:15 UTC. It is kept here as a record.
No stronger detection stands among the 8 recorded within 20 km of this point since 24 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 May 26 at 6:41PM MDT until May 26 at 7:15PM MDT by NWS Great Falls MT
An estimated 66,281 people live within 50 km of this point.
Nearby, since 24 April 2026
- May 13, 2026 · score 39 · 17.6 km
How we know
Confirmed by 4 independent sources, including NOAA.
Our own score for this event is 39 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 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) | 39 / 100 |
| Our confidence | 91% |
| Coordinates | 46.3619, -112.2231 |
| Nearest City | Helena (29 km) |
| Population Exposed | 66.3K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-05-27T00:41:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.c474b9ff5dac779a31ef184bd37f5612615487e1.001.1 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Broadwater, MT; Jefferson, MT |
| Headline | Severe Thunderstorm Warning issued May 26 at 6:41PM MDT until May 26 at 7:15PM MDT by NWS Great Falls MT |
| Expires | 2026-05-26T19:15:00-06:00 |
| SenderName | NWS Great Falls MT |
| HasExactCoords | true |
| Iem TypeSummary | G |
| Iem Magnitude | 72 |
| Iem Unit | MPH |
| Iem City | 3 WNW Townsend |
| Iem County | Broadwater |
| Iem State | MT |
| Iem Wfo | TFX |
| Iem Remark | Mesonet station GINM8 Ginger RAWS. |
| MergedSources | [{"id":"iem_G_46.180_-111.440_1779839100000","source":"iem","severity":"low","severityValue":25,"timestamp":1779839100000,"latitude":46.18,"longitude":-111.44},{"id":"iem_G_46.130_-111.980_1779840000000","source":"iem","severity":"low","severityValue":25,"timestamp":1779840000000,"latitude":46.13,"longitude":-111.98},{"id":"iem_G_46.330_-111.590_1779840180000","source":"iem","severity":"low","severityValue":25,"timestamp":1779840180000,"latitude":46.33,"longitude":-111.59}] |
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 near Helena?
Calamity.live data shows a weather event with CalamityScore 39/100, near Helena (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.