As the climate phenomenon La Nina prepares to make another appearance this fall, meteorologists are predicting a season of stormy and wet weather for some parts of Canada and mild, dry temperatures for others.
Though the continued strong presence of La Nina is abnormal, AccuWeather’s senior meteorologist Brett Anderson says this will leave less room for surprises this fall season.
“This’ll be the first time we’ve had the third straight La Nina fall in 20 years, so it’s abnormal but that also gives us some confidence with the forecast,” he told CTVNews.ca in a phone interview on Friday.
La Nina, which causes cooler-than-normal sea surface temperatures, often impacts jet streams across North America, bringing in strong wind patterns. Here’s how this could impact the weather across the country, according to AccuWeather.
WEST COAST BRACES FOR STORMS
Similar to last fall, British Columbia is expected to have a wet and rainy season, potentially raising the risk of flooding.
Anderson said burn scars left from the wildfires over the past two summers could also increase the risk of mudslides as the terrain becomes more susceptible to this extreme weather.
“They had a lot of big fires in British Columbia last year and those burn scars still exist. So with stormy patterns certainly later in the fall and into the winter, that could be trouble for flash floods out in those areas,” he said.
DRY TEMPERATURES TO HELP WITH PRAIRIES HARVEST
Moving away from the Pacific, temperatures are expected to become mild and dry along the Prairies. AccuWeather is forecasting warmer-than-normal temperatures, particularly in Saskatchewan and Manitoba.
“In the Prairies we are predicting we’ll see drier conditions this fall especially central, eastern Prairies and warmer-than-normal conditions,” Anderson said.
Ultimately, this makes for good news for these regions, Anderson said, as the drier temperatures will favour the harvest season.
DELAYED FALL FOLIAGE FOR EASTERN CANADA
Similar to the Prairies, Eastern Canada should expect warmer and drier temperatures during the first half of the season. As long as temperatures don’t become too warm, Anderson said this could make for excellent fall foliage even if it’s a bit delayed.
“We’re looking at a delayed peak, probably about a week later than usual but I think the colours will be in pretty good shape,” he said.
During the later fall season, however, La Nina is expected to ramp up the rain and cold, leading up to the winter season across Ontario and Quebec.
“This (La Nina) will keep most of the chilly air up across Northwestern Canada while allowing a lot of Pacific air to continue to flood across the nation and keep much of central and eastern Canada warmer than normal throughout much of the fall, though I think things may start to change as we get towards November,” he said.
‘HIGHER THAN USUAL’ THREAT FOR TROPICAL STORMS IN THE MARITIMES
Over in the Atlantic, warmer water temperatures could potentially heighten the risk of tropical storms.
“The hurricane season is off to a very slow start with nothing going on in August but there are signs that things can really start to pick up starting next week and the week after that,” he said.
Though tropical storms don’t usually reach the Maritimes, Anderson said there’s always a chance of that, especially with above-normal temperatures and rainfall, particularly in Newfoundland and Labrador.
“It’s probably higher than usual this fall across Atlantic Canada,” Anderson said.