After record April, still ice on the Great Lakes

Sunday, May 4, 2014, 2:37 PM -

After an unseasonably cold April, no one will be surprised to find the Great Lakes saw its greatest April ice cover since record keeping began in 1973.

On April 1, almost 70 per cent of the lakes' surface was covered, down to around 24 per cent at the end of the month. All this after a maximum ice coverage of 92.2 per cent, recorded in early March, that was the second-highest ice cover ever recorded.

The last levels, taken on May 3, put the coverage level at 21 per cent, according to the Great Lakes Environmental Research Laboratory.

But now that we're into May, of course, the question many people are likely asking is: Will the lakes be completely clear by the Victoria Day weekend?

The answer is 'yes', provided you don't live on Lake Superior.

The Canadian Ice Service released its monthly ice outlook on May 1, and many sites along Canada's Lake Superior shores are expected to still be clearing slowly of ice by the end of the month.

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That includes Thunder Bay, with some areas, such as southern Lake Superior west of the Keweenaw Peninsula, are even expected to still have some areas of "very thick lake ice" within 10 to 20 nautical miles of the shore.

Some spots on Lake Huron and Georgian Bay could still see some ice, but with mostly open water, while Lake Erie and Lake Ontario are all completely ice free.

The water, however, may not be quite as warm for any May Two-Four dips. Environment Canada says average May air temperatures are expected to be below normal on Lake Superior, and normal to below normal elsewhere.

Although this past winter's maximum ice coverage was the second-highest on record, the U.S. National Climatic Data Centre says that's not a trend pointing to consistently colder winters

Image: NOAA

In fact, they say quite the opposite.

"The near-record large ice cover for the Great Lakes this cold season is contrary to the long-term ice decline for the lakes," the centre says. "Between 1973 and 2010, Great Lakes ice cover was down 71 percent. In 2002, the Great Lakes ice cover was record low at 9.5 percent, and just two years ago the ice covered only 12.9 percent of the lakes during the winter."

The expanded ice cover this winter caused transportation difficulties for lake traffic, and decreased the amount of water evaporating from the lakes in winter and spring.