While winds have cleared the air above Vancouver for now, wildfire smoke is expected to return to the city this weekend.
The smoke the city saw last weekend was cleared by a change in winds, Environment Canada meteorologist Alyssa Charbonneau tells V.I.A., but things are expected to change again by Friday (Aug. 25), with outflow winds pushing the smoke from the interior to the coast.
"We are expecting that we're going to switch back," she says. "A ridge of high pressure over the interior of the province is building."
The high-pressure ridge mixed with low pressure on the coast will see easterly winds carrying the smoke that's built up over the fires in the Shuswap, Okanagan, and other areas.
Computer models consistently show winds carrying smoke to Vancouver this weekend, but how much smoke will come to the coast is still unclear.
"It does look like we could see the potential for air quality impacts, but how bad they would be...I don't have a good sense of that right now," Charbonneau says. "People should keep an eye on the forecast and alerts from Metro Vancouver or the province for air quality."
The uncertainty is due to a number of factors. There are lots of fires contributing smoke in the interior and many have calmed after cooler, wetter weather. But that ridge of high pressure means dry conditions and fires could grow.
At the same time, it's unclear how much smoke will build up in the interior before it gets pushed to the coast; smoke conditions over Kelowna and Kamloops over the next couple of days will give an idea of what Vancouver may see Friday and over the weekend.
"It's quite possible we'll see smoke linger on Saturday and maybe on Sunday as well," says Charbonneau. "It's hard to say if it'll be widespread or localized."
At the same time, there's some instability on the coast which will affect smoke. Notably, on the edge of the forecast, some instability is expected, around Tuesday, Aug. 29. That could bring showers to the area and new wind patterns that would clear the air in Metro Vancouver.
Charbonneau says the smoke situation will become more certain closer to the weekend as predictions for wind patterns and other factors become more certain.
V.I.A.'s Weatherhood keeps track of air quality in different Vancouver neighbourhoods; each neighbourhood can be bookmarked for hyper-local forecasts and current conditions.
