Near-record ice cover on Lake Ontario

Glenn Coin | [email protected] 
on February 18, 2015 at 4:29 PM, updated February 19, 2015 at 10:13 AM


Update: The ice continues to cover more of Lake Ontario each day. The latest report shows that the lake was 82.6 percent covered as of Wednesday.

Syracuse, N.Y. -- The amount of ice covering Lake Ontario has reached near-record levels, and scientists say that's the result of two cold winters in a row.

One result of all the ice is that Central and Northern New York are getting less lake effect snow than they would otherwise. Extensive ice cover reduces evaporation, the raw ingredient for lake effect snow.

On Tuesday, ice covered 78.5 percent of the surface area of Lake Ontario. That comes close to the record of 85.7 percent, set on Feb. 19, 1979.

This much ice is highly unusual on Lake Ontario, which generally has the least ice cover of any of the five Great Lakes. The long-term average for Lake Ontario, in fact, is just 11 percent. Ontario is particularly deep compared to its surface, so it retains heat better than the other lakes and is less likely to freeze.

What's happening this year is that the lake never fully warmed up after last year's cold winter and relatively cool summer. Those cooler waters, combined with with a bitterly cold January and February this year, create lots of ice.

"The lake lost a lot of heat last year and it never regained it during the summer," explained George Leshkevich, a physical scientist at the Great Lakes Environmental Research Laboratory in Michigan. "We're starting out with cooler water temperatures, and with these cold temps we've been having the lake is just in a condition where it can form substantial ice cover."

A year ago, ice covered 32 percent of Lake Ontario. The greatest ice cover, 61.5 percent, occurred on March 6.

See what the Great Lakes looked like a year ago.

Last year's winter was not just cold, but long. Syracuse had the fifth-coldest March on record.

This winter has been bitterly cold, too. January temperatures were below normal, and February 2015 could be the coldest month on record in Syracuse. Watertown, at the east end of Lake Ontario, was the coldest spot in the contiguous United States twice in the past week.

View full sizeMaximum ice cover for Lake Ontario since 1973.Great Lakes Environmental Research Laboratory 
On Tuesday, the overall ice cover for all five Great Lakes was 82.3 percent. A year ago, it was nearly the same, at 81.6 percent.

On Lake Ontario, all the additional ice at this time of year means that Syracuse is getting less lake effect snow than it would if the lake were more open, said National Weather Service meteorologist Dave Nicosia. Lake effect snow is caused when cold winds sweep across long lakes, pick up moisture and then drop that moisture as snow on the colder land.

"There's lot of ice on the lake, so we're not getting as much moisture," Nicosia said. "It is definitely cutting down on our lake effect."

Despite that, this February has been one of the snowiest on record in Syracuse, with 39.7 inches falling already. A typical February has 25.3 inches.

With more cold weather coming, Nicosia said Lake Ontario could accumulate even more ice.

"We have two to three more weeks to build more ice," he said. "I've never seen this much ice on Lake Ontario in 20 years of watching."