This alert expired on 12 August 2026 at 12:30 UTC. It is kept here as a record.
It is the 7th strongest of the 85 detections recorded within 20 km of this point since 11 March 2026. 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 August 12 at 6:39AM CDT until August 12 at 7:30AM CDT by NWS Quad Cities IA IL
An estimated 278,494 people live within 50 km of this point.
Nearby, since 11 March 2026
- July 7, 2026 · score 43 · 1.9 km
- June 18, 2026 · score 37 · 10.4 km
- March 11, 2026 · score 49 · 10.4 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 43 out of 100, at 86 % 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) | 43 / 100 |
| Our confidence | 86% |
| Coordinates | 41.7477, -91.4852 |
| Nearest City | North Liberty (10 km) |
| Population Exposed | 278.5K within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-12T11:39:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.421262cf4cd73a2b2e4699226c419735 |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Benton, IA; Iowa, IA; Rock Island, IL; Cedar, IA; Clinton, IA; Muscatine, IA; Scott, IA |
| Headline | Severe Thunderstorm Warning issued August 12 at 6:39AM CDT until August 12 at 7:30AM CDT by NWS Quad Cities IA IL |
| Expires | 2026-08-12T07:30:00-05:00 |
| SenderName | NWS Quad Cities IA IL |
| HasExactCoords | true |
| MergedCount | 2 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.421262cf4cd73a2b2e4699226c419735b7782731.001.1","noaa_urn:oid:2.49.0.1.840.0.2187ee8763aae7962d727f1a4d7b89677ec57d87.001.1"] |
| Iem TypeSummary | G |
| Iem Magnitude | 58 |
| Iem Unit | MPH |
| Iem City | 1 NW Atalissa |
| Iem County | Muscatine |
| Iem State | IA |
| Iem Wfo | DVN |
| MergedSources | [{"id":"iem_G_41.580_-91.180_1786533180000","source":"iem","severity":"low","severityValue":25,"timestamp":1786533180000,"latitude":41.58,"longitude":-91.18}] |
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 43/100, near North Liberty (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.