Heavy Freezing Spray Warning Issued for Western Lake Superior Through Monday Morning

Alert Details

The National Weather Service in Marquette, MI, has issued a Heavy Freezing Spray Warning for portions of Lake Superior. This alert indicates that conditions are favorable for significant ice accumulation on vessels, which poses a severe risk to maritime safety.

Affected Areas

The warning specifically covers Lake Superior west of a line from Saxon Harbor, WI, to Grand Portage, MN, beyond 5 nautical miles (5NM) from the shore.

What You Should Do

Mariners are strongly advised to take the following precautions:

• Prepare for dangerous and rapid accumulation of ice on vessels.
• If possible, remain in port until conditions improve.
• Avoid the warning area entirely.
• If caught in these conditions, conduct immediate ice mitigation efforts to maintain vessel integrity.

Expected Conditions

According to the NWS, heavy freezing spray is occurring at a rate of 2 cm per hour or greater. This level of spray can lead to rapid ice accretion on decks and superstructures. Such accumulation is extremely hazardous as it may render mechanical and electronic components inoperative and can result in a catastrophic loss of stability for the vessel.

Timeline

The warning is effective immediately and will remain in place until 7:00 AM EST (6:00 AM CST) on Monday, February 23, 2026.