This alert expired on 11 August 2026 at 15:30 UTC. It is kept here as a record.
It is the 5th strongest of the 44 detections recorded within 20 km of this point since 10 March 2026. Another comparable one was recorded here earlier the same day. 9 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 11 at 10:09AM CDT until August 11 at 10:30AM CDT by NWS Lincoln IL
An estimated 1,045,946 people live within 50 km of this point.
Nearby, since 10 March 2026
- June 11, 2026 · score 46 · 8.3 km
- March 11, 2026 · score 58 · 11.7 km
- March 10, 2026 · score 58 · 11.7 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 52 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) | 52 / 100 |
| Our confidence | 81% |
| Coordinates | 41.5102, -88.5475 |
| Nearest City | Yorkville (17 km) |
| Population Exposed | 1.0M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-11T15:09:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.2792b581438464675c6fe1130506b21e |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Marshall, IL; Lee, IL; Ogle, IL; Winnebago, IL; Jasper, IN; Porter, IN and 6 more areas |
| Headline | Severe Thunderstorm Warning issued August 11 at 10:09AM CDT until August 11 at 10:30AM CDT by NWS Lincoln IL |
| Expires | 2026-08-11T10:30:00-05:00 |
| SenderName | NWS Lincoln IL |
| HasExactCoords | true |
| MergedCount | 9 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.2792b581438464675c6fe1130506b21e38664987.001.1","noaa_urn:oid:2.49.0.1.840.0.dcd1cb7c66db63471d451f99483be34247101d35.001.1","noaa_urn:oid:2.49.0.1.840.0.9d9e82653f700e0134f3b2a7cc4c4aa6c76107c1.002.1","noaa_urn:oid:2.49.0.1.840.0.66d41639c8d0aed3f29b7de9d5957f7bd72c9fa4.001.1","noaa_urn:oid:2.49.0.1.840.0.8d7f2d04ec06a752c5d21965e96f56413e420763.001.1","noaa_urn:oid:2.49.0.1.840.0.9128fd9909c32edde18ee252332ba02440b5a572.001.1","noaa_urn:oid:2.49.0.1.840.0.7500f3386839025fa8c59ec4ce87f593a0af5c54.001.1","noaa_urn:oid:2.49.0.1.840.0.546436958ec8c86b0b01ba62bcc9e12bdc225473.001.1","noaa_urn:oid:2.49.0.1.840.0.ce39bbbe9b1c1c314a8556f3294807e0ca31c873.001.1"] |
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 Yorkville?
Calamity.live data shows a weather event with CalamityScore 52/100, near Yorkville (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 188 scientific monitoring sources.