Avalanche danger high across B.C., Alta.

The Canadian Avalanche Centre has issued a "special" warning the avalanche risk will be high in the southern B.C. backcountry in the coming days.

The risk is also high in areas of Alberta.

Forecasters say a recent dump of snow, along with high winds and upcoming sunshine, could lead to disaster.

The Canadian Avalanche Centre has issued a special warning for the South Coast, North Columbias, South Columbias and Kootenay-Boundary regions. The risk is also high in the southern Alberta Rockies, Kananaskis, Banff, Yoho, Kootenay and Jasper.

A recent storm dumped more than one metre of snow on areas of B.C. in recent days, and another 30 to 40 centimetres is expected to fall before the weekend.

James Floyer, a forecaster with the avalanche centre in Revelstoke, said slab avalanches more likely in the coming days.

Floyer said the problem is a weak layer, buried underneath new snow, that's extremely unstable. The layer can easily slide if triggered by humans.  

"Where you get slab avalanches, you get a large piece of the mountain acting as a single unit, and those are very, very dangerous," he said.

Officials fear the upcoming sparkling, clear winter days will draw unwary skiers, boarders and sledders into the backcountry, where weak layers in the snowpack create the perfect conditions for tragedy.

"During periods of clear weather, when the riding conditions are quite good, a lot of people will be getting out, yet there's still dangerous or very dangerous conditions in the mountains," avalanche forecaster Cam Campbell said.

Alberta hasn't had the snow B.C. is receiving, but conditions are still dangerous.

"Generally what we're looking at in the Rockies is oftentimes is a shallower, colder faceted snowpack with a weaker base and a lot of wind effect as well and areas that are wind exposed can have highly variable snowpack depths," Campbell said.

The avalanche centre said people should reconsider their backcountry travel plans until the risk subsides.

Forecasters say anyone venturing into untracked powder outside regulated ski areas should carry a shovel, probe and transceiver — and be ready to use them.

Southern Interior highways closed

The avalanche risk in B.C.'s southern Interior forced the closure of several highways on Friday.

The Trans-Canada Highway is closed in both directions from Golden to West Boundary of Yoho National Park as highway crews complete avalanche control work. Officials estimated the highway would reopen by 3 p.m. PT.

Similar work is causing long delays over the Kootenay Pass on Highway 3.

Highway 23  was closed in both directions at Mica Dam hill because of a high avalanche hazard. The highway was expected to reopen Saturday afternoon.

The high avalanche risk also forced the closure of Highway 31 in both directions at Lardeau Bluff. It was expected the road would be open by Friday afternoon.

Travellers are advised to check the Ministry of Transportation website for updates.