This alert expired on 10 August 2026 at 05:45 UTC. It is kept here as a record.
No stronger detection stands among the 30 recorded within 20 km of this point since 8 June 2026 — 13 others scored the same. Another comparable one was recorded here earlier the same day. 8 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued August 10 at 12:20AM CDT until August 10 at 12:45AM CDT by NWS Chicago IL
An estimated 4,865,604 people live within 50 km of this point.
Nearby, since 8 June 2026
- August 9, 2026 · score 52 · 5.0 km
- July 27, 2026 · score 52 · 6.5 km
- August 11, 2026 · score 52 · 8.1 km
How we know
Confirmed by 2 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 86 % 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 | 86% |
| Coordinates | 42.1766, -87.3446 |
| Nearest City | Evanston (32 km) |
| Population Exposed | 4.9M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-10T05:20:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.695d932765dd5518d3a72f93e6943b11 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Winthrop Harbor to Wilmette Harbor IL; Wilmette Harbor to Northerly Island IL; Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5NM offshore to Mid Lake; Lake Michigan from Wilmette Harbor to Michigan City in 5NM offshore to Mid Lake; Lake Michigan from Wind Point WI to Winthrop Harbor IL 5NM offshore to Mid Lake; Wilmette Harbor to Northerly Island IL; Northerly Island to Calumet Harbor IL; Calumet Harbor IL to Gary IN; Gary to Burns Harbor IN; Burns Harbor to Michigan City IN; Lake Michigan from Wilmette Harbor to Michigan City in 5NM offshore to Mid Lake |
| Headline | Special Marine Warning issued August 10 at 12:20AM CDT until August 10 at 12:45AM CDT by NWS Chicago IL |
| Expires | 2026-08-10T00:45:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| MergedCount | 3 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.695d932765dd5518d3a72f93e6943b110ba5aceb.001.1","noaa_urn:oid:2.49.0.1.840.0.88891ae1101d26ce6b17b828edd10d7edb1eb3ca.001.1","noaa_urn:oid:2.49.0.1.840.0.8fa507a0ee85e31b9082a57882ce2a5200dc9dc4.001.1"] |
| Iem TypeSummary | H |
| Iem Magnitude | 1 |
| Iem Unit | Inch |
| Iem City | Vernon Hills |
| Iem County | Lake |
| Iem State | IL |
| Iem Wfo | LOT |
| Iem Remark | Trained spotter reports quarter size hail ongoing in Vernon Hills. |
| MergedSources | [{"id":"iem_H_42.240_-87.970_1786334580000","source":"iem","severity":"low","severityValue":25,"timestamp":1786334580000,"latitude":42.24,"longitude":-87.97}] |
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.