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Special Marine Warning for Northerly Island to Calumet Harbor IL; Lake Michigan from Wilmette Harbor to Michigan City in 5NM offshore to Mid Lake

Official alert fields

What you need to know

Effective
Ends or expires
Official severity
Severe
Official urgency
Immediate
Official certainty
Likely

What is happening

For the following areas... Nearshore Waters from Northerly Island to Calumet Harbor... Open Waters from Wilmette Harbor to Michigan City out to Mid Lake... At 1031 PM CDT, strong thunderstorms were located along a line extending from 14 nm north of Burns Harbor to 6 nm southeast of Harrison-Dever Crib to near 59th...

What the bulletin says to do

Move to safe harbor until hazardous weather passes.

Read official NWS bulletin

Full official description

Bulletin details

For the following areas... Nearshore Waters from Northerly Island to Calumet Harbor... Open Waters from Wilmette Harbor to Michigan City out to Mid Lake... At 1031 PM CDT, strong thunderstorms were located along a line extending from 14 nm north of Burns Harbor to 6 nm southeast of Harrison-Dever Crib to near 59th Street Marina, moving east at 35 knots. HAZARD...Wind gusts 34 knots or greater. SOURCE...Radar indicated. IMPACT...Small craft could be damaged in briefly higher winds and suddenly higher waves. Locations impacted include... Calumet Harbor, 31st Street Harbor, Burnham Harbor, Jackson Park Harbor, and 59th Street Marina.

Official geometry where available

Alert boundary

Lifecycle record

Official revisions

5 captured
  1. Update

    Special Marine Warning issued August 18 at 10:31PM CDT until August 18 at 11:15PM CDT by NWS Chicago IL

    Official revision
  2. Update

    Special Marine Warning issued August 18 at 10:21PM CDT until August 18 at 11:15PM CDT by NWS Chicago IL

    Official revision
  3. Update

    Special Marine Warning issued August 18 at 10:07PM CDT until August 18 at 11:15PM CDT by NWS Chicago IL

    Official revision
  4. Update

    Special Marine Warning issued August 18 at 9:43PM CDT until August 18 at 11:15PM CDT by NWS Chicago IL

    Official revision
  5. Alert

    Special Marine Warning issued August 18 at 9:18PM CDT until August 18 at 11:15PM CDT by NWS Chicago IL

    Official revision

Source and limitations

Publisher: Weather Alert Watch. Primary source: NWS Chicago IL. This page reorganizes official fields and does not add a forecast or expand the affected area.

CAP status
Actual
Message type
Update
Last collected
Methodology and corrections