‘Risks of thunderstorm and heavy rainfall’: Here’s what the weather will be like across Canada this week

CTV meteorologist Kelsey McEwen says this week will be a mixed bag for parts of Canada.

It will be cloudy and rainy in some parts of the country this week as a weather system slowly moves north from the United States and initially brings periods of heavy rain to areas of Ontario and Quebec, according to Kelsey McEwen, chief meteorologist and co-host of CTV’s Your Morning.

The southern half of Ontario and Quebec will have the soggiest outlook, with thunderstorms and rain showers on and off in the afternoon and evening for the first few days, McEwen said. The conditions will clear up and it will become drier and sunny by Thursday and Friday, she added.

“I will say it’s not a severe weather system right now, but one of the greatest risks from it will be the isolated risks of thunderstorm and heavy rainfall,” McEwen said in a phone interview with CTVNews.ca on Monday.

She forecasts 20 to 40 millimetres of rain for the affected areas in Ontario and Quebec, with the risk of isolated thunderstorms from Monday through Wednesday “as the system is very slow-moving eastward.”

Meanwhile, it will be “sunny and very warm” in the northern communities of Ontario and Quebec.

The same weather system hitting the two provinces will then move into Atlantic Canada on Tuesday night and last until the end of the week, she said. The Maritimes will see periods of heavy rainfall and thunderstorms, McEwen added. Snow is even expected in Labrador on Wednesday night, with mainly rain and a chance of snow in Newfoundland’s northern peninsula on Thursday, she said.

A “disturbance” is sliding through the Prairies, with some rainfall through parts of Saskatchewan that should end Monday night, McEwen said. But after the soggy spell, the weather will be “incredibly dry and very warm” as temperatures rise in Alberta and Saskatchewan, she added, noting the current wildfire near Grande Prairie, Alta.

It’s a different story in British Columbia.

“B.C. is seeing the frontal system move onshore over a couple of days to bring rain and snow, typically north of Vancouver Island,” she said.

McEwen said a weather system will move onto the coastline, bringing rainy conditions.

Portions of the Interior and northern B.C. will see some rain and snow, and the central coast will see the highest amount of precipitation Tuesday, she added.