This alert expired on 11 June 2026 at 14:45 UTC. It is kept here as a record.
No stronger detection stands among the 78 recorded within 20 km of this point since 11 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 9:30AM CDT until June 11 at 9:45AM CDT by NWS Quad Cities IA IL
An estimated 278,494 people live within 50 km of this point.
Nearby, since 11 March 2026
- June 18, 2026 · score 37 · 3.8 km
- July 7, 2026 · score 43 · 11.3 km
- June 18, 2026 · score 49 · 12.9 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 67 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 | critical |
| Calamity Score (ours) | 67 / 100 |
| Our confidence | 81% |
| Coordinates | 41.7788, -91.6350 |
| Nearest City | North Liberty (4 km) |
| Population Exposed | 278.5K within 50 km |
| Impact Tier | severe |
| Timestamp | 2026-06-11T14:30:00.000Z |
| Source | https://api.weather.gov/alerts/urn:oid:2.49.0.1.840.0.fabcbcef62046645f9cb17c5c46a6d335b3c7275.002.1 |
Score Breakdown
Technical Details
| Event | Tornado Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Johnson, IA; Linn, IA |
| Headline | Tornado Warning issued June 11 at 9:30AM CDT until June 11 at 9:45AM CDT by NWS Quad Cities IA IL |
| Expires | 2026-06-11T09:45:00-05:00 |
| SenderName | NWS Quad Cities IA IL |
| 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 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 67/100, near North Liberty (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.