HOUGHTON - Lake Superior is nearly three-quarters iced over and forecasters said there's a possibility it will be covered completely before winter's end for the first time since the winter of 1996-97.
But even without 100 percent ice cover, the situation will likely have a major effect on weather along the shore for the remainder of the season.
"The big impact we'll see is shutting down the lake effect snow," said Guy Meadows, director of Michigan Tech University's Great Lakes Research Center.
Lake effect snow occurs when weather systems from the north and west pick up evaporating lake water that's warmer than the air, then drop it as snow after reaching land. Ice cover blocks that evaporation.
But the ice could also contribute to more frigid temperatures, Meadows said, as the warmer lake water won't have the chance to moderate the temperatures of those same northerly weather systems.
George Leshkevich, a scientist with NOAA's CoastWatch team, said the only large area of open water left on Lake Superior is over its deepest area, in the eastern basin between Keweenaw Bay and Whitefish Bay.