This alert expired on 9 August 2026 at 20:00 UTC. It is kept here as a record.
No stronger detection stands among the 36 recorded within 20 km of this point since 8 June 2026 — 15 others scored the same. The last comparable one was on 27 July 2026. 6 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Severe Thunderstorm Warning issued August 9 at 2:37PM EDT until August 9 at 4:00PM EDT by NWS Grand Rapids MI
An estimated 4,343,949 people live within 50 km of this point.
Nearby, since 8 June 2026
- August 10, 2026 · score 52 · 5.0 km
- June 12, 2026 · score 46 · 6.7 km
- July 27, 2026 · score 52 · 8.7 km
How we know
Confirmed by 10 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 91 % 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 | Medium |
| Calamity Score (ours) | 52 / 100 |
| Our confidence | 91% |
| Coordinates | 42.1639, -87.2861 |
| Nearest City | Rogers Park (36 km) |
| Population Exposed | 4.3M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-09T18:37:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Severe Thunderstorm Warning_noaa_urn:oid:2.49.0.1.840.0.1ed299abf3342943baa59afb82bf39ff |
Score Breakdown
Technical Details
| Event | Severe Thunderstorm Warning |
| Urgency | Immediate |
| Certainty | Observed |
| AreaDesc | Allegan, MI; Ottawa, MI; Cook, IL; DuPage, IL; DuPage, IL; Kane, IL; Kendall, IL; Will, IL |
| Headline | Severe Thunderstorm Warning issued August 9 at 2:37PM EDT until August 9 at 4:00PM EDT by NWS Grand Rapids MI |
| Expires | 2026-08-09T16:00:00-04:00 |
| SenderName | NWS Grand Rapids MI |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.1ed299abf3342943baa59afb82bf39ff5df58961.001.1","noaa_urn:oid:2.49.0.1.840.0.d9098f5ed8690cf8bb00f6cff06ec82508459981.002.1","noaa_urn:oid:2.49.0.1.840.0.1a39d7cf59816daa5fc9b508d1931cf3ec83fa71.001.1"] |
| Iem TypeSummary | R |
| Iem Magnitude | 1.9 |
| Iem Unit | Inch |
| Iem City | Gages Lake |
| Iem County | Lake |
| Iem State | IL |
| Iem Wfo | LOT |
| Iem Remark | Cocorahs station IL-LK-105 Gages Lake 0.4 SSW. |
| Google News RssFeed | weather |
| Google News SourceName | NBC 5 Chicago |
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 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 in this area?
Calamity.live data shows a weather event with CalamityScore 52/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.