Polar vortex drives Great Lakes to highest ice cover in 20 years

The chill from the recent polar vortex means the Great Lakes are seeing more ice coverage earlier than normal this year.

Ice coverage on Lake Erie, for example, has reached 90 percent in recent days.

"There are many benefits from increased ice cover on the Great Lakes," wrote Paul Huttner on the MPR News Updraft blog.

"More ice cover means less evaporation. That can help sustain lake levels," Huttner said. "Another benefit is that ice cover largely shuts down the prolific lake-effect snow squalls that dump snow by the foot downwind from the Great Lakes."

Huttner and Jay Austin from the Large Lake Observatory at the University of Minnesota-Duluth join Kerri Miller to discuss how this early ice cover fits in with larger trends.