Wildfire smoke drifts across Canada, over parts of U.S., prompting air quality advisories

Air quality advisories are in effect across Western Canada as smoky conditions plague some areas, according to the latest forecasts.

As the wildfire season gets underway, here's where smoke may be an issue.

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In northeastern B.C., smoke from the fires triggered an air quality warning Monday. The smoke from this area is expected to push into Alberta Tuesday morning, CTV Your Morning's meteorologist Kelsey McEwen said.

Central and northern Alberta communities are also under an air quality warning Monday as thick smoke moves northeast, a trend expected to continue through Tuesday. Very dense smoke will be present in the area over the next two days, the forecast suggests.

However, McEwen said, smoky conditions are improving for most of the province.

In central Saskatchewan, some communities face smoke thick enough to prompt warnings of reduced visibility. Smoke will travel south, hitting Regina, Yorkton and Brandon, Man., by Monday afternoon, according to the forecast. Further north, it's expected to be smoky in Saskatoon on Wednesday morning.

Manitoba's border with Saskatchewan is also under an air quality warning, and smoke is set to land in Winnipeg on Tuesday morning.

Smoke from the Prairies will reduce air quality in northern Ontario as well. McEwen says the smoke will hit central Ontario, Sudbury and North Bay on Tuesday morning.

Further south, smoke is expected to drift in and linger Tuesday morning along Lake Erie from Windsor up to Niagara, and along Lake Ontario from Hamilton to Kingston.

There is a possibility of haze in Ottawa and Montreal from Monday through Tuesday. Smoke could travel as far as Quebec City on Tuesday morning.

Aside from smoke, a thunderstorm is expected over central and southwest Ontario and the Golden Horseshoe. The storms could bring strong winds, nickel-sized hail and heavy rainfall.

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According to Environment Canada, a frost advisory was issued for parts of Nova Scotia as temperatures are expected to reach the freezing mark, with cooler temperatures in low lying areas.

Areas include Kings, Digby, Shelburne and Yarmouth counties.

The frost advisory is mainly in the province's western mainland and forecast to last until Tuesday morning.

The weather agency warned that frost may damage some crops in frost-prone areas.

In the Northwest Territories, smoke will sit over Great Slave Lake while conditions improve over Fort Liard and Fort Simpson. In parts of western Nunavut, very dense smoke is expected over the next two days.

Wildfire season

The Canadian Interagency Forest Fire Centre reported that, as of May 9, around 90 fires were burning across Canada, including 12 that were classified as out of control.

Of the current fires, 40 are burning in Alberta, 24 in British Columbia and 10 in Manitoba. The four fires burning in New Brunswick are the only ones in Atlantic Canada, while Ontario has two and Quebec one.

The fire forecast for the rest of May and June shows an elevated risk across Western Canada except for the west coast of British Columbia. There is a very high to extreme risk in much of southern and central Saskatchewan, parts of northern Alberta and the interior of British Columbia.

Most of Ontario and western Quebec are at moderate risk, while eastern Quebec and Atlantic Canada show low risk.

In May, most of Yukon, Northwest Territories and part of southern Nunavut are at high risk of fires. In June, the risk extends to very high and extreme.

U.S. air quality warnings

Smoke from Canadian wildfires has prompted health warnings across the upper Midwest for the second straight year.

Fires raging in British Columbia and Alberta sent the haze over parts of Montana, the Dakotas, Minnesota and Wisconsin on Sunday, lingering into Monday morning.

The smoke has prompted these states to issue air quality alerts, some of which have expired, urging people to remain indoors and to avoid heavy outdoor labour.

At least some smoke could drift as far south as Iowa and Chicago, leaving skies looking milky by late Tuesday or early Wednesday, said Rafal Ogorek, a meteorologist in the National Weather Service's Chicago office.

With files from The Canadian Press and The Associated Press