Wildfires west of Calgary add to veil of smoke blowing in from B.C.

Wildfires burning near Banff National Park are contributing to the blanket of smoke over southern Alberta.

A fire that sparked near Lac des Arcs, east of Canmore, on Friday eveningwas classified as held on Saturday after itburned 10 hectares of forest (about the size of 15 city blocks).

Alberta Parks closed Razors Edge Trail in Bow Valley Provincial Park due to the nearby fire.

Two other fires, about 60 kilometres north of the Banff townsiteand outsideof the national park's border, continueto burn out of control. Thosefires had consumed 100 hectares and 27 hectares as of Saturday morning.

Derrick Forsythe, a wildfire information officer with the province, said weather conditions looked promising for the 384 wildland firefighters currently working across Alberta.

"We've had no concerns on the weather expressed so far today. We always keep an eye on that because that's one of the things wildfire firefighters are trained to look out for, because when wind shifts, we have to be aware of what's going on as they're working on the fire," he said.

Evacuations ongoing in B.C.

As of Saturday morning, there were 58 wildfires burning across Alberta, three of which were out of control. Nearly 50,000 hectares have burned in the province's forest protection areas so far this year.

But much of the smoke settling in across Calgary and southern Alberta was from out of province.

More than 20,000 properties in B.C. were under evacuation order or alert on Saturdaydue to hundreds of fires, most of which were burning in the province's interior. There are also many large fires burning in the northwestern U.S.

And, while the wind was forecasted to blow eastward throughout the weekend, a shift in direction could see smoke drift into Albertafrom fires burning in northern Saskatchewan.

Environment and Climate Change Canada has issued air quality alerts for Calgary and southern Alberta.The Air Quality Health Index was forecasted to hit 7 or high risk in Calgary on Saturday evening.

Scientists say extreme weather events like heat waves are becoming more frequent as a result of climate change, whichincreases wildfire riskas forests dry out and many fires are ignited by lightning strikes.

Fire danger ratings continue to be high across most of Alberta due to hot and dry conditions. Fire bans are in place for Banff, Kootenay and Yoho National Parks.