Natalie Thomas, reporter
January 11, 2012 — Natalie Thomas talks to meteorologist Gina Ressler to find out why this year's winter doesn't look so Canadian.
There are many theories floating around as to why we've seen such warm weather. Gina Ressler, a meteorologist at The Weather Network, says we have the jet stream to blame -- or for some people, thank -- for this unseasonable weather.
“The northern branch of the jet stream that flows from west to east across the country has been extremely stronger than normal,“ Ressler explains.“So what that does, it actually keeps that Arctic air locked in place over the Arctic.“
“So the cold air’s there but this jet stream just hasn’t allowed it to push down south.“
Ressler explains that the strong jet stream in the North has been keeping the jet energy further north than usual. This means we're seeing a dominant high pressure area in Western Canada, which has been keeping a large part of the country dry with snowfall amounts far below average.
Ressler also says that the same jet stream that's bringing warm weather to Canada is responsible for the wild weather that's been seen in Alaska and Scotland this year.
Some people think that La Nina is the reason we've seen a warm and dry winter -- but Ressler says this isn't true.
“La Nina is still going on. And that is a pattern of cooler than normal ocean temperatures in the Pacific ocean. But typically with La Nina we usually see cooler than normal temperatures in the western half of the country,“ she says. “But the La Nina pattern just hasn’t manifested itself into the atmosphere over North America this year, like it did last year.“
“La Nina is associated with certain weather patterns some of the time, not necessarily true all of the time.“
The Prairies have seen the most out of character weather this winter. Several temperature records -- some dating back as far as 100 years -- have been broken.
But Ressler says that according to long-range models, the jet stream pattern is starting to break down. “We can expect the cold Arctic air to start to make its way down into the Prairies and out East as well,“ Ressler says.
“We still have a lot of time left, so we're not out of the woods yet.“