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Special Marine Warning for Marquette to Munising MI; Munising to Grand Marais MI; Lake Superior East of a line from Manitou Island to Marquette MI and West of a line from Grand Marais MI to the US/Canadian Border Beyond 5NM from shore

This alert has ended.Kept for recent context. Do not use it as a current warning.

Official alert fields

What you need to know

Effective
Ended
Official severity
Severe
Official urgency
Immediate
Official certainty
Likely

What is happening

For the following areas... Lake Superior East of a line from Manitou Island to Marquette MI and West of a line from Grand Marais MI to the US/Canadian Border Beyond 5NM from shore... Marquette to Munising MI... Munising to Grand Marais MI... At 647 PM EDT, a severe thunderstorm capable of producing waterspouts was...

What the bulletin says to do

A Tornado Watch remains in effect until midnight EDT for north central Upper Michigan...and the adjacent waters of Lake Superior. Move to safe harbor until hazardous weather passes.

Read official NWS bulletin

Full official description

Bulletin details

For the following areas... Lake Superior East of a line from Manitou Island to Marquette MI and West of a line from Grand Marais MI to the US/Canadian Border Beyond 5NM from shore... Marquette to Munising MI... Munising to Grand Marais MI... At 647 PM EDT, a severe thunderstorm capable of producing waterspouts was located over Au Train Island, or near Shelter Bay, moving east at 45 knots. HAZARD...Waterspouts, wind gusts to 40 knots, and small hail. SOURCE...Radar indicated. IMPACT...Waterspouts can easily overturn boats and create locally hazardous seas. Small craft could be damaged in briefly higher winds and suddenly higher waves. Locations impacted include... Laughing Whitefish Point, Shot Point, Shelter Bay, Grand Island, and Au Train Island.

Lifecycle record

Official revisions

3 captured
  1. Update

    Special Marine Warning issued July 20 at 6:48PM EDT until July 20 at 7:00PM EDT by NWS Marquette MI

    Official revision
  2. Update

    Special Marine Warning issued July 20 at 6:27PM EDT until July 20 at 7:00PM EDT by NWS Marquette MI

    Official revision
  3. Alert

    Special Marine Warning issued July 20 at 6:03PM EDT until July 20 at 7:00PM EDT by NWS Marquette MI

    Official revision

Source and limitations

Publisher: Weather Alert Watch. Primary source: NWS Marquette MI. 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