This alert expired on 9 August 2026 at 19:00 UTC. It is kept here as a record.
It is the 3rd strongest of the 23 detections recorded within 20 km of this point since 6 June 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: Special Marine Warning issued August 9 at 12:56PM CDT until August 9 at 2:00PM CDT by NWS Chicago IL
Nearby, since 6 June 2026
- June 12, 2026 · score 16 · 5.3 km
- July 27, 2026 · score 22 · 8.5 km
- August 9, 2026 · score 22 · 14.6 km
How we know
One source: NOAA. Not yet confirmed by a second, independent source.
Our own score for this event is 22 out of 100, at 61 % 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) | 22 / 100 |
| Our confidence | 61% |
| Coordinates | 42.4769, -87.1935 |
| Nearest City | Zion (52 km) |
| Impact Tier | minor |
| Timestamp | 2026-08-09T17:56:00.000Z |
| Source | https://api.weather.gov/alerts/merged_Special Marine Warning_noaa_urn:oid:2.49.0.1.840.0.74ded44a1a8efc0e93c1dff799e4e867 |
Score Breakdown
Technical Details
| Event | Special Marine Warning |
| Urgency | Immediate |
| Certainty | Likely |
| AreaDesc | Winthrop Harbor to Wilmette Harbor IL; Lake Michigan from Winthrop Harbor to Wilmette 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; Lake Michigan from Sheboygan to Port Washington WI 5NM offshore to Mid Lake; Lake Michigan from Port Washington to North Point Light WI 5NM offshore to Mid Lake; Lake Michigan from North Point Light to Wind Point WI 5NM offshore to Mid Lake; Lake Michigan from Wind Point WI to Winthrop Harbor IL 5NM offshore to Mid Lake and 1 more areas |
| Headline | Special Marine Warning issued August 9 at 12:56PM CDT until August 9 at 2:00PM CDT by NWS Chicago IL |
| Expires | 2026-08-09T14:00:00-05:00 |
| SenderName | NWS Chicago IL |
| HasExactCoords | true |
| MergedCount | 4 |
| MergedIds | ["noaa_urn:oid:2.49.0.1.840.0.74ded44a1a8efc0e93c1dff799e4e8673663fe29.001.1","noaa_urn:oid:2.49.0.1.840.0.fc75b397116f24682159b5256239a5482df5d36e.001.1","noaa_urn:oid:2.49.0.1.840.0.38c912b60be0a518f53d2fba4938839a101bcef9.001.1","noaa_urn:oid:2.49.0.1.840.0.d4ab2c35929b01b6a0afbbc3c6472c8c3e59e4f1.001.1"] |
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 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 22/100 (United States), based on data from noaa. Source: Calamity.live, a platform aggregating real-time data from 185 scientific monitoring sources.