Heavy Freezing Spray and Storm Warnings Issued for Grand Portage to Grand Marais MN

Alert Details

The National Weather Service in Duluth, MN, has issued a Heavy Freezing Spray Warning, a Storm Warning, and a Gale Warning for the Lake Superior coastal waters. These alerts indicate severe marine conditions that pose a significant threat to vessel stability and safety.

Affected Areas

The warning area specifically covers the region from Grand Portage to Grand Marais, MN (Zone LSZ140).

What You Should Do

Mariners are strongly advised to remain in port or alter course to avoid the warning area. If at sea, mariners should prepare for dangerous accumulation of ice on their vessels and conduct immediate mitigation. Vessels should be secured for severe conditions, including storm-force winds and hazardous waves.

Expected Conditions

• Freezing Spray: Heavy freezing spray is expected at a rate of 2 cm per hour or greater, which may cause rapid ice accretion on decks and superstructures.
• Wind: Northeast winds of 20 to 30 knots with gusts up to 40 knots are expected during the Gale Warning. During the Storm Warning, north winds will increase to 25 to 35 knots with gusts reaching 50 knots.
• Waves: Wave heights are forecast to range between 5 and 8 feet.
• Impacts: Rapid ice accumulation can lead to a catastrophic loss of vessel stability and render mechanical or electronic components inoperative. Storm-force winds and waves may capsize or damage vessels and significantly reduce visibility.

Timeline

• Gale Warning: Effective from 4:00 AM to 7:00 PM CDT Sunday.
• Heavy Freezing Spray Warning: Effective from 7:00 AM Sunday to 4:00 PM CDT Monday.
• Storm Warning: Effective from 7:00 PM Sunday to 4:00 PM CDT Monday.