Weather forecaster calls for warm, dry fall
Stay tuned for more of the same in Calgary.
AccuWeather released its fall forecast for Canada on Wednesday and the signs point to a warm and dry autumn in southern Alberta.
This means there’s unlikely to be a Snowtember repeat, although AccuWeather senior meteorologist Brett Anderson said freak events can’t be predicted in a long- term forecast.
“Odds are against it,” Anderson said. “You never know, of course, but I’d say the pattern would argue against it.”
The warmth, around 1- 2 degrees C above normal for most of the fall in southern Alberta, and up to 2- 3 degrees warmer than usual in the mountains, is partly the result of El Nino weather patterns and the warm water in the Pacific.
El Nino can break up the jet stream across North America, causing it to split in two, said Anderson. This pushes the southern end of the stream, which is warmer and wetter, further south and pushes the colder northern end further north. Calgary will be in the middle of these zones.
“Normally in winter we have one jet stream and that fluctuates. North of the jet stream it gets cold and south of the jet stream it’s warm and right along the jet stream it’s stormy, you get rain and snow and whatnot,” Anderson said.
“During El Nino, the jet stream splits into two, so what happens is the southern side of the jet stream, that’s where all the rain, the big storms are, the northern side of the jet stream that shifts farther north ... that keeps all the cold air farther north ... so that kind of leaves Western Canada out of the cold and also out of the storminess.”
AccuWeather predicts the first frost will likely be later than normal this year in Alberta, and ski season will be shortened due to a lack of snow in the late fall. The forecast covers September to November, when we’re expected to have the highest above average temperatures in southern Alberta, 2- 3 degrees above normal.
“We may see more of a typical, close to the normal in September but then as you go later and later, things will continue to go farther above normal than what we’re used to seeing,” Anderson said.
He also said the trend will probably continue into the colder months.
“Signs point toward a mild winter across Western Canada.”
Anderson said Alberta won’t be totally dry. He expects southern Alberta could see higher than normal rainfall in early September with normal rainfall in the mountains.