This alert expired on 12 August 2026 at 16:30 UTC. It is kept here as a record.
It is the 2nd strongest of the 77 detections recorded within 20 km of this point since 10 March 2026. Another comparable one was recorded here earlier the same day. 15 more were recorded here in the fortnight before it.
What the source measured
NOAA reported: Special Marine Warning issued August 12 at 10:06AM CDT until August 12 at 11:30AM CDT by NWS Chicago IL
An estimated 6,325,516 people live within 50 km of this point.
Nearby, since 10 March 2026
- July 27, 2026 · score 52 · 0.0 km
- June 11, 2026 · score 46 · 1.1 km
- July 4, 2026 · score 52 · 1.4 km
How we know
Confirmed by 5 independent sources, including NOAA.
Our own score for this event is 52 out of 100, at 90 % 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 | 90% |
| Coordinates | 41.7842, -87.3568 |
| Nearest City | South Chicago (17 km) |
| Population Exposed | 6.3M within 50 km |
| Impact Tier | significant |
| Timestamp | 2026-08-12T15:06:00.000Z |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | 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 12 at 10:06AM CDT until August 12 at 11:30AM CDT by NWS Chicago IL |
| Expires | 2026-08-12T11:30:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| Google News RssFeed | weather |
| Google News SourceName | facebook.com |
| MergedSources | [{"id":"gnews_weather_496258_196","source":"google_news","severity":"medium","severityValue":40,"timestamp":1786531604000,"latitude":41.85,"longitude":-87.65},{"id":"gnews_weather_496258_197","source":"google_news","severity":"medium","severityValue":40,"timestamp":1786532346000,"latitude":41.85,"longitude":-87.65},{"id":"gnews_weather_496261_200","source":"google_news","severity":"medium","severityValue":40,"timestamp":1786539988000,"latitude":41.85,"longitude":-87.65},{"id":"gnews_weather_496262_206","source":"google_news","severity":"medium","severityValue":40,"timestamp":1786545140000,"latitude":41.85,"longitude":-87.65}] |
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 52/100, near South Chicago (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 191 scientific monitoring sources.