This alert expired on 30 August 2026 at 20:45 UTC. It is kept here as a record.
No stronger detection stands among the 274 recorded within 20 km of this point since 15 March 2026 — 11 others scored the same. Another comparable one was recorded here earlier the same day.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 30 at 2:27PM MDT until August 30 at 2:45PM MDT by NWS Denver CO
An estimated 2,565,771 people live within 50 km of this point.
Nearby, since 15 March 2026
- August 30, 2026 · score 52 · 5.0 km
- July 24, 2026 · score 46 · 5.8 km
- May 6, 2026 · score 52 · 11.4 km
How we know
Confirmed by 3 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 90 % 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) | 52 / 100 |
| Our confidence | 90% |
| Coordinates | 39.8546, -105.1854 |
| Nearest City | Arvada (10 km) |
| Population Exposed | 2.6M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-30T20:27:00.000Z |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Southwest Boulder, CO; Southeast Boulder, CO; Broomfield, CO; Jefferson, CO |
| Headline | Severe Thunderstorm Warning issued August 30 at 2:27PM MDT until August 30 at 2:45PM MDT by NWS Denver CO |
| Expires | 2026-08-30T14:45:00-06:00 |
| SenderName | NWS Denver CO |
| HasExactCoords | true |
| Spc ReportType | wind |
| Spc Speed | 60 |
| Spc Location | 3 N White Ranch Open Sp |
| Spc County | Jefferson |
| Spc State | CO |
| Spc Comments | (BOU) |
| MergedSources | [{"id":"spc_wind_39.76_-105.68_6","source":"spc","severity":"medium","severityValue":45,"timestamp":1788119400000,"latitude":39.76,"longitude":-105.68},{"id":"spc_wind_39.86_-105.29_7","source":"spc","severity":"medium","severityValue":45,"timestamp":1788120960000,"latitude":39.86,"longitude":-105.29}] |
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.
Calamity.live data shows a weather event with CalamityScore 52/100, near Arvada (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 191 scientific monitoring sources.