This alert expired on 25 June 2026 at 21:00 UTC. It is kept here as a record.
No stronger detection stands among the 18 recorded within 20 km of this point since 13 May 2026 — 12 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 June 25 at 2:40PM MDT until June 25 at 3:00PM MDT by NWS Great Falls MT
An estimated 32,091 people live within 50 km of this point.
Nearby, since 13 May 2026
- July 18, 2026 · score 34 · 18.1 km
- July 23, 2026 · score 34 · 18.4 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 34 out of 100, at 81 % confidence.
The score is ours, computed from intensity, exposed population and local history — not the source’s.
Event Data
| Type | Severe weather |
| Severity | medium |
| Calamity Score (ours) | 34 / 100 |
| Our confidence | 81% |
| Coordinates | 46.8090, -111.8300 |
| Nearest City | Helena (29 km) |
| Population Exposed | 32.1K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-06-25T20:40:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.d40fe281c68c6621c20a589caa887a1f |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Broadwater, MT; Jefferson, MT; Lewis and Clark, MT; Cascade, MT; Lewis and Clark, MT |
| Headline | Severe Thunderstorm Warning issued June 25 at 2:40PM MDT until June 25 at 3:00PM MDT by NWS Great Falls MT |
| Expires | 2026-06-25T15:00:00-06:00 |
| SenderName | NWS Great Falls MT |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.d40fe281c68c6621c20a589caa887a1f878459db.001.1","noaa_urn:oid:2.49.0.1.840.0.7dab975957e442457dc2ee76a9d1257b5e11196f.001.1"] |
| Iem TypeSummary | H |
| Iem Magnitude | 1 |
| Iem Unit | Inch |
| Iem City | 6 NNW Helena |
| Iem County | Lewis and Clark |
| Iem State | MT |
| Iem Wfo | TFX |
| Iem Remark | Mostly nickel sized hail with a few quarter sized mixed in. |
| MergedSources | [{"id":"iem_H_46.690_-112.060_1782418140000","source":"iem","severity":"low","severityValue":25,"timestamp":1782418140000,"latitude":46.69,"longitude":-112.06}] |
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 10 February 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 34/100, near Helena (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.