British Columbia·Video

When will it end? Rain could clear smoky South Coast skies

A rainy summer weekend in Vancouver? Bring it on. Environment Canada says a change could clear the air after more than a week of smoke-filled skies on the South Coast

A change in winds Friday and cold front Saturday could help air quality — and possibly firefighters

Smoke from wildfires across the province fills the air in Vancouver. (Dillon Hodgin/CBC)

A rainy summer weekend in Vancouver? Bring it on.

Environment Canada says a change is coming that could clear smoke-filled skies on the South Coast and possibly help with wildfire-fighting efforts in the B.C. Interior.

The first step is forecast for Friday, where winds from the south are forecast to blow the lingering smoke inland and away from the coast.

"There is a trough of low pressure coming this weekend, so, as early as Friday, we will see some southwesterly wind aloft, pushing into the South Coast," said meteorologist Cindy Yu.

Then, a cold front is expected, bringing rain for Saturday night and Sunday.

"We are hoping that will redeposit some of the fine particulates back onto the ground so it will clear out our air."

It's also expected to cool the region back to seasonal temperatures in the low 20s.

For now, an air quality advisory remains in place for Metro Vancouver and the Fraser Valley.

Johanna Wagstaffe explains the impact of winds and sinking air on wildfire smoke 2:16

'Very unusual' lingering smoke

People living in parts of the Interior have dealt with smoky skies for a month as hundreds of wildfires burned there.

At certain points, air quality — normally measured on a scale from 1 to 10 — reached a cough-inducing 36 in Williams Lake and 49 in Kamloops, both considered "very high risk."

Twitter user Aaron Neels posted these comparisons from his view in Chilliwack, B.C., to show how thick the smoke is on Aug. 2, 2017. (@aaron_neels/Twitter)

Watch smoke arrive

In the Vancouver area, smoke rolled in late July 31 as outflow winds pushed air from the Interior to the coast.

The fine particulate matter was visible — but high in the atmosphere — on Aug. 1 before socking in lower levels the following day.

Winds from the Interior happen regularly, but the lingering smoke, cradled by the topography of the South Coast, is uncommon, said Yu.

"The extent of the smoke is actually very unusual."

The Sea-to-Sky corridor, where Whistler also saw "very high risk" air last week on the Air Quality Health Index, is also expected to see some clearing with the forecast rain, but it may take longer at higher elevations.

A child swings at a park in East Vancouver at sunset on Aug. 1, before smoke that had lingered at higher elevations began mixing down Wednesday leading to lower air quality. (Lisa Johnson/CBC)