Marine Fog Alert: Visibility Near Zero on Western Lake Superior Through 9 A.M. Friday!
DULUTH, MN — Boaters and shoreline communities near western Lake Superior should prepare for dangerously reduced visibility, as dense marine fog is expected to persist through 9 a.m. Friday. The National Weather Service has issued a Marine Dense Fog Advisory for the western waters of Lake Superior, including Duluth, Two Harbors, and the surrounding nearshore zones.
What to Expect: Visibility on the lake could fall below a quarter mile at times due to the thick fog, especially during the overnight and early morning hours. The fog is being caused by warm, moist air flowing over the cold lake surface — a common setup in spring that often leads to sudden and severe visibility drops.
Boating Safety Concerns: Boaters are strongly urged to delay any non-essential travel until conditions improve. If you’re already on the water, reduce your speed, use navigation lights, and sound fog signals regularly to alert other vessels of your position. GPS and radar systems can help, but extra caution is advised.
Shoreline Impact: Coastal residents and visitors may also notice reduced visibility and damp, misty conditions along the shorelines, particularly in areas from Duluth to Silver Bay. Drivers near the lakeshore should slow down and use headlights in low-visibility areas.
When Will It Clear? The dense fog is expected to gradually lift after 9 a.m. Friday, as winds shift and temperatures rise, improving visibility throughout the day. However, lingering patches of fog may still be possible in shaded or low-lying areas near the lake into late morning.
