The tune the Great Lakes are currently singing: Ice ice baby. And they're singing it a lot sooner than they did last year.
Twenty percent of the Great Lakes are covered by ice, according to the National Oceanic and Atmospheric Administration's Great Lakes Environmental Research Laboratory in Ann Arbor.
This same time last year, only 3.1 percent of the lakes were covered by ice, the research laboratory said.
"Most people who are anywhere near a lake or have been outside at all have probably noticed it's certainly been cold enough," said Anne Clites, a physical scientist at the laboratory.
The government laboratory conducts scientific research on the Great Lakes and its coastal ecosystems.
Clites said it's not that odd for the lakes to have as much ice as they do at this time of year.
"The thing about ice cover is it varies incredibly from one year to the next," she said. "But for ice to grow as much as it has in the last 10 days is not that unusual at all."
"I think people are surprised because the fall was so warm and many meteorologists were predicting we were going to have a fairly warm winter as recently as early December," Clites said. "But by the end of December, the forecasts flipped to cold, which is generating the ice."
She said winter weather will cause some lakes to get completely covered by ice while others won't.
For example, she said, Lake Erie is frequently 90 percent covered by ice in the dead of winter.
Lake Erie is the shallowest of the Great Lakes and as a result, the fastest to freeze. Its maximum depth is about 210 feet.
"The different lakes have different patterns, characteristics, shape and depth," Clites said. "But Lake Michigan rarely gets that much ice cover."
Lake Michigan's maximum depth is about 925 feet. The deepest lake, Superior, has a maximum depth of 1,332 feet, according to the Environmental Protection Agency.
At any rate, the quickly freezing lakes are already causing problems for the shipping industry.
Earlier this week, the U.S. Coast Guard deployed two of its ice-breaking tugboats to free several vessels in western Lake Erie and the St. Clair River.
Officials with the Coast Guard's 9th District, which covers the Great Lakes and is based in Cleveland, said three ships got stuck in ice on Lake Erie Monday and Tuesday.
The first, the John J. Boland, was broken out of the ice by the Coast Guard's Morro Bay tugboat on Wednesday.
The Morro Bay freed the Hon. Paul J. Martin from the ice on western Lake Erie Tuesday and was broken out by the Morro Bay.
The third vessel, the James R. Barker, got stuck twice Tuesday on western Lake Erie. After the first time it got stuck, a tugboat called the Calusa Coast broke it free. It was beset by ice again and the Morro Bay freed it.
Closer to home, the Indiana Harbor became stuck in the ice of the St. Clair River Tuesday and had to be freed by the Coast Guard's Neah Bay tug.
Officials aren't expecting the situation to improve anytime soon.
"Currently, ice coverage on Lake Erie is over 20%, well above the seasonal norm of 5% for this time of year," Coast Guard officials said this week in a statement. "Weather reports indicate that Lake Erie will build up more ice over the next week."
The Coast Guard said it will continue to have its cutters break ice on the Great Lakes to make sure the waterways stay navigable for cargo ships until the shipping season ends on Jan. 15.
Clites said the laboratory's forecast for Great Lakes ice coverage this year calls for a little more ice than last year. The 2018 forecast predicts about 60 percent of the lakes to be covered by ice. The long term average is about 55 percent, according to the laboratory.
"But not much more," she said. "Not like in 2014 or 2015 or other years when he had a massive amount of ice. We're not expecting that, but probably more than last year."