What's behind all the wild weather in Canada this summer?

Zoom in on nearly any part of Canada this summer and you're likely to find people suffering from various forms of extreme weather.
Intense storms in Western Canada have caused severe flooding, particularly in Manitoba. Parts of Ontario, Quebec and B.C. have been under heat waves and thunderstorm watches, while the North has been plagued by wildfires — and that's a non-exhaustive list.
Just this week, a storm ripped apart a house in southwest Winnipeg, tearing down fences and throwing barbecues across yards. Kingston, Ont., was briefly under a tornado warning on Tuesday, while Canada Day celebrations in Ottawa were cancelled amid thunderstorms and flooding.
"We've had a lot of wild weather," said Jennifer Smith, an Ottawa-based meteorologist with Environment and Climate Change Canada.
Many climate monitors have been predicting an extra-strong El Niño this year that's expected to peak in the winter. But the summer season has already brought chaos and devastation for many Canadians. What's going on?
How jet stream, El Niño could impact weatherIn terms of this summer's weather, it's still too early in the season to draw any clear conclusions, said Barrie Bonsal, a Saskatoon-based research scientist with Environment and Climate Change Canada.
El Niño conditions — when the surface waters of the central to eastern tropical Pacific are warmer than average — were only declared on June 11, according to the U.S. Climate Prediction Center.
"Canada has a very variable climate. It's usually hot somewhere, cold somewhere, wet somewhere, dry somewhere," he said. "It's a big country and that's just normal."
Cross Country Checkup is asking: How are floods, wildfires and extreme weather events changing your summer? Leave your comment here and we may read it or call you back for Sunday's show.
The jet stream could be one factor in the summer weather, he said.
That refers to the fast-flowing boundary of air high in the atmosphere that flows west to east and separates the north's cold air from warmer air from the south.
If it gets stuck in a certain position — as it recently has — that can cause different forms of extreme weather in different areas, like heat waves and droughts.

We're also transitioning from several colder La Niña years to a strong El Niño, which can explain some of the summer tumult, said Doug Gillham, senior meteorologist at the Weather Network, as El Niño itself is typically felt more prominently in the winter here in Canada.
"The change in the atmosphere is rarely smooth sailing," he said. "Spring's always a roller coaster, but the roller coaster's been a little extra wild … and it hasn't quite stopped yet."
The "super" El Niño that some are predicting is expected to exacerbate extreme weather, causing some regions to whiplash between severe drought and dangerously heavy rains. In Canada, however, that usually means milder winters, and fewer hurricanes in the Atlantic region.

In Western Canada, the weather is expected to be more consistently warm — and much drier in the south — for the rest of the summer, experts told CBC News.
And while there will be dry spells, droughts are unlikely in the Prairies, Gillham said, though they remain a concern in parts of B.C.
From the Great Lakes to the Maritimes, temperatures are expected to cool down a touch, compared to the heat wave people are currently experiencing.
However, that doesn't mean a perfect, storm-free summer ahead. As is the case with most forecasting matters, Gillham says there are no guarantees: "The roller coaster will settle down, but it's not going to stop."

Heading into the winter, another result of El Niño is that the southern U.S. gets much wetter — and there's a small chance that moisture could circulate up north to the southern Prairies, said Bonsal, though this is unlikely.
"You know, I wouldn't bet the farm on it."
How you can prepareAll three experts said staying informed is key in preparing for the weather this summer. Stay hydrated in periods of extreme heat, said Smith, and try to find a cool space and check on vulnerable people if you can.
Meanwhile, if there are thunderstorms in your area, Smith says people should move inside immediately, suggesting, "When thunder roars, go indoors."
Bonsal advises using history as a guide for what to expect in the seasons ahead, while also being prepared for potentially more intense, warmer weather in the years to come.
He says he's frequently hearing people on the news express that they've never seen weather like this in their lifetime: "I think it's telling us something, that these impacts are getting stronger."

There's no clear link between global warming and El Niño, which is naturally occurring. But climate change may make El Niño events stronger when they do take place, says Bonsal, who wrote his PhD thesis on the phenomenon.
"We are poking Mother Nature with a stick a bit here by warming the atmosphere."
Smith also says climate change is likely playing the largest role in our summer weather.
"Canada is warming at roughly double the global rate and close to four times that in the Arctic," she said. "This intensifies the baseline that drives extreme, record-breaking summer heat and erratic precipitation across the country."
Still, Gillham cautioned against attributing weather patterns solely to one cause, likening it to figuring out why a team won or lost a hockey game.
"The 'why' questions in weather are just about never going to be one- or two-word answers. It is a complex relationship between many variables," he said. "It's rarely just one player."
cbc.ca



