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What is the fallout from the Great Lakes ice coverage? If you're a summer cottager, pay attention.

Extensive ice coverage on the Great Lakes could result in a shorter swim season

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Andrea Bagley
Digital Reporter

Friday, March 7, 2014, 12:08 PM -

If you have a cottage or simply enjoy heading to the beach, "don't expect to comfortably swim until well after the May long weekend."

That's according to Weather Network meteorologist Dayna Vettese, who says the ice coverage on the Great Lakes is nearing record levels.

"As of March 6, 92.2% of the Great Lakes were covered," Vettese says. "This is the most coverage we have seen since the 70’s."


How does this compare to other winters?

Vettese: Record highest ice coverage was 94.7% in 1979. Lowest on record was 9.5% in 2002. Ice coverage in 2012-2013 was about 38%.

How covered is Lake Ontario specifically and how does this compare to other winters? Why does Lake Ontario not freeze over like the other lakes?

Vettese: As of March 5, Lake Ontario is 47% covered in ice. The last time Lake Ontario froze over completely was 1934. Lake Ontario normally doesn't freeze complete due to a few factors: It is a deep lake so it holds on to its milder water for longer and requires more energy to cool it off and freeze. It is at a lower latitude than Lake Superior so it is in a relatively milder climate. Lake Erie is even further south, but it freezes over because it is a relatively shallow lake making it easier to cool off in the winter.

What could this mean come spring and summer? Will it keep our temperatures around the lakes cooler? Will people not be able to swim at their cottages until later?

Vettese: We need to keep an eye on things such as ice jams come spring. With all of this ice, we need to keep an eye on the possibility of ice jams and flooding resulting from that. The longer the ice remains in the Great Lakes, the shorter period the lakes have to warm up in the spring and summer. This means come summertime, the lakes will feel colder than they have in previous years. Cooler lakes also mean slightly cooler lake fronts so being on the beaches of Lakes Erie, Ontario, Huron and Georgian Bay will feel cooler than areas further inland.


As of Thursday, Toronto Fire Service have been breaking ice for the ferry routes for 81 consecutive days. The previous record was 78 days set back in the winter of 2001-2002.

"Crews say that wildlife has really been affected in the area as well," says The Weather Network's Natalie Thomas who reported from the Toronto Harbour on Thursday. "Coyotes are being spotted on the island, which never happens. But this winter they can walk to the island across the frozen lake."

Swans have also become frozen in the ice, so crews have had to bring out warm water to help them break free.

"We started ice breaking on December the 16th. We’re out, every day," says David Nickerson, Marine Captain with Toronto Fire Services. "We start at 5 in the morning and we’re breaking ice routes. We’ll go out occasionally two to three times a day and more...It’d be nice if the sun keeps shining and if we could have some warm temperatures and if we had some favourable winds, maybe from the north, they would flush out some of the ice that we break up outside the harbour."

The Great Lakes are inching closer to all-time ice cover record
NASA image shows extensive ice coverage of the Great Lakes
Lake Superior reaching full ice-up

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