This alert expired on 11 June 2026 at 12:45 UTC. It is kept here as a record.
No stronger detection stands among the 81 recorded within 20 km of this point since 16 March 2026 — one other scored the same. Another comparable one was recorded here earlier the same day. One more was recorded here in the fortnight before it.
What the source measured
NOAA reported: Tornado Warning issued June 11 at 7:39AM CDT until June 11 at 7:45AM CDT by NWS Des Moines IA
An estimated 516,424 people live within 50 km of this point.
Nearby, since 16 March 2026
- July 2, 2026 · score 48 · 13.5 km
- August 13, 2026 · score 48 · 13.6 km
- July 4, 2026 · score 48 · 14.0 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 72 out of 100, at 81 % 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 | Critical |
| Calamity Score (ours) | 72 / 100 |
| Our confidence | 81% |
| Coordinates | 41.8540, -93.6960 |
| Nearest City | Ankeny (16 km) |
| Population Exposed | 516.4K within 50 km |
| Impact Tier | catastrophic |
| Timestamp | 2026-06-11T12:39:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.e84fc61dcf4d9fa2f3a837960c6efdd1eeaf2f3a.002.1 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Boone, IA; Polk, IA; Story, IA |
| Headline | Tornado Warning issued June 11 at 7:39AM CDT until June 11 at 7:45AM CDT by NWS Des Moines IA |
| Expires | 2026-06-11T07:45:00-05:00 |
| SenderName | NWS Des Moines IA |
| HasExactCoords | true |
Safety Information
If a tornado warning is issued: go to a basement or an interior room on the lowest floor, away from windows. A vehicle and a mobile home are not shelter. Cover your head and neck. Wait for the official all-clear before going outside, and watch for downed power lines and gas leaks afterwards.
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 Ankeny?
Calamity.live data shows a weather event with CalamityScore 72/100, near Ankeny (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.