Heavy Freezing Spray Warning Issued for Lake Superior

Alert Details

A Heavy Freezing Spray Warning has been issued by the National Weather Service (NWS) in Marquette, MI. The alert signifies a high likelihood of rapid ice accumulation on vessels, which can lead to hazardous maritime conditions.

Affected Areas

The warning covers Lake Superior from Saxon Harbor, WI, to the Upper Entrance to Portage Canal, MI. The alert area extends 5 nautical miles offshore to the U.S./Canadian border and specifically includes Isle Royale National Park.

What You Should Do

Mariners are urged to prepare for dangerous accumulation of ice on their vessels. The NWS recommends that, if possible, vessels should remain in port or avoid the warning area entirely. If transit is necessary, mariners should conduct mitigation efforts to manage ice buildup.

Expected Conditions

Heavy freezing spray is expected to occur at a rate of 2 cm per hour or greater. This spray may rapidly accumulate on vessels, potentially rendering mechanical and electronic components inoperative. Rapid ice accretion on decks and superstructures is particularly dangerous as it may result in a catastrophic loss of stability for the vessel.

Timeline

The warning is scheduled to take effect at 7:00 AM EST on Sunday, February 22, 2026. The alert is expected to remain in place until 1:00 AM EST on Monday, February 23, 2026.