This summer has been so warm that the Great Lakes are as much as 8 degrees Centigrade above their normal temperatures. The Hamilton Spectator.
(Aug 13, 2010) The combination of an unseasonably mild winter and spring followed by a hot summer has led to record-breaking water temperatures in the Great Lakes. Lake Superior is a stunning 8° C above normal for this time of year—and the big lake they call Gitche Gumee will get warmer still for another few weeks.
“It’s really remarkable,” said Jay Austin, a professor at the University of Minnesota-Duluth’s Large Lakes Observatory. “The surface waters on Superior at one site are over 70 degrees Fahrenheit right now (21° C),” Austin added. “Usually, Lake Superior doesn’t break 60 (16° C).”
Lake Michigan has also reached record temperatures, at about 4° C above normal. The other three Great Lakes haven’t set records, but they are all above normal. As recently as last weekend, Lake Ontario’s surface temperatures reached 24 C, and by early July, Lake Erie had reached 27 C. “That’s bath water,” said Austin.
The warm water is a result of an unusually warm winter, which drastically reduced the amount of ice that formed across the Great Lakes, but most particularly in Lake Superior. Austin said he preferred to hedge his bets when asked to explain why there was so little ice cover. Part of the reason, he said, was the natural cycle of an El Nino winter in 2009-10, which traditionally means milder weather in eastern Canada. “But at the same time, it’s on top of a general trend over the last 30 years towards less ice and warmer summers and that trend is consistent with the whole idea of climate change,” Austin added….
That doesn’t necessarily mean that we’ll have a mild winter.
“Work that we did a few years ago showed that winter conditions will play a very important role in determining what happens the following summer,” said Austin. “But it doesn’t appear that it works the other way around….
What we might enjoy, however, is a slower decline into winter, said Environment Canada senior climatologist David Phillips. “It may take a little longer for the ice to form and it may also mean huge amounts of lake-effect snow,” said Phillips. “It’s so Canadian to worry about winter when we’re still in the middle of summer,” he added with a chuckle.
What has surprised Phillips is the consistency of warmth that southern Ontario has enjoyed since last fall. Nine of the past 10 months have been warmer than normal, and we’re on track to set a record for the warmest first eight months of a year. And there’s no end in sight, Phillips noted happily. Environment Canada’s medium-range forecast predicts above-normal temperatures for southern Ontario for the rest of August, September, October and November.