Marquette, MI – Ice is expected to rapidly build on boats at rates up to 2 centimeters per hour this afternoon, creating life-threatening conditions across Lake Superior before sunset.
According to the National Weather Service in Marquette, a Heavy Freezing Spray Warning remains in effect until 8 p.m. Monday for much of Lake Superior, with Gale Warnings continuing through early evening in several zones. Wind gusts could reach 40 to 45 knots, generating waves between 6 and 12 feet.
The most dangerous conditions are expected from Marquette to Munising and east toward Grand Marais and Whitefish Point, where freezing spray will accumulate quickly on decks and equipment. Nearshore areas, including the Portage Canal and Eagle River, are also under Small Craft Advisories through early Tuesday as winds remain elevated overnight.
These conditions can disable navigation systems and add significant weight to vessels, increasing the risk of capsizing. Mariners are urged to remain in port or seek safe harbor immediately, especially between 5 p.m. and 8 p.m. when freezing spray intensifies.
Winds will gradually ease overnight, but hazardous waves and lingering ice accumulation may continue into early Tuesday, with additional marine advisories possible.
