Heavy Freezing Spray Warning Issued for Lake Superior Near Isle Royale National Park
This alert is no longer in effect.
NOAA issued it on April 6, 2026, 4 months ago. Warnings of this kind stay in effect for hours to a few days, so this page is a historical record of what was issued, not a current warning. For conditions where you are right now, check weather.gov (US), weather.gc.ca (Canada), the Met Office (UK), or the Bureau of Meteorology (Australia).
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The National Weather Service has issued a Heavy Freezing Spray Warning for Lake Superior, with ice accumulation rates of 2 cm per hour expected to create hazardous maritime conditions.
Read this weather record in 30 seconds
- Record type
- Heavy Freezing Spray Warning
- Affected area
- Lake Superior
- Issued
- April 6, 2026
- Issuing authority
- NWS Marquette
The warning type, named area, and issue time define this record. Confirm all three against the original agency notice before treating it as current.
Record status: historical. It was issued 4 months ago; use the issuing agency's live warning service for current conditions in Lake Superior.
Alert Details
A Heavy Freezing Spray Warning has been issued by the National Weather Service (NWS) Marquette MI. This alert signifies a severe maritime hazard where freezing spray is expected to accumulate rapidly on vessels.
Affected Areas
The warning covers Lake Superior from Saxon Harbor, Wisconsin, to the Upper Entrance to Portage Canal, Michigan. The affected zone extends 5 nautical miles offshore to the U.S./Canadian border and includes Isle Royale National Park.
What You Should Do
Mariners are advised to prepare for dangerous accumulations of ice on their vessels. The NWS recommends that operators remain in port if possible, avoid the warning area entirely, or conduct immediate mitigation efforts to manage ice buildup.
Expected Conditions
Heavy freezing spray is forecast to occur at a rate of 2 cm per hour or greater. This rapid ice accretion on decks and superstructures can lead to a catastrophic loss of vessel stability. Additionally, freezing spray may render critical mechanical and electronic components inoperative, further endangering those on the water.
Timeline
The warning is effective starting at 4:00 AM EST on Tuesday, February 24. The hazardous conditions are expected to persist until the warning expires at 1:00 PM EST on Tuesday.
Original source: NOAA Official Notice ↗
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