Ahead of warm weekend, avalanche experts continue to urge caution in the backcountry

While skiers might be eyeing the mountain backcountry this weekend as a chinook brings a surge of warm air to the region, avalanche experts continue to caution that the snowpack is particularly weak this season and large avalanches are possible.

Lisa Larson, with Avalanche Canada's South Rockies Field Team, said warm weather typically increases snowpack density, especially after a cold spell such as the one southern Alberta experienced this week.

However, this weekend also looks to bring blustery winds and fresh snow, making wind slab conditions more likely across the mountains, on which there sits one of the weakest snowpack bases experts have seen in a decade.

"We encourage backcountry users to be on the lookout for signs of instability," Larson said, adding that one of the common signs of unstable snow are shooting cracks.

While persistent weak layer issues have been a factor over the last few days in the British Columbia Interior, Larson explained that wind slab issues could pose a bigger concern over the weekend in B.C.'s southeast corner and in the Crowsnest Pass area in southern Alberta. 

Doug Latimer, an avalanche forecaster and the lead winter guide for the Alpine Club of Canada, said the underlying weakness of the snowpack could pose a problem through the end of the season.

"If you're going into the backcountry this weekend, by all means get out and enjoy yourself, but understand that we're in a situation where, regardless of what the avalanche bulletin says, there's always going to be this underlying threat," he said. 

The weak layer was formed, he explained, by the snow and extreme cold in the early part of the season. This turned the early snow into ball bearing-like crystals on which the snow that fell over the holidays amassed on top, creating the possibility for avalanches big enough to bury cars.

He advised backcountry skiers to stay in safer terrain, such as low-angle slopes and areas where there are lots of trees. As for those steep, aggressive lines, he suggests waiting perhaps until next season.

"We've just got to wait this [season] out," he said. "Chances are we're gonna see quite a few good years up ahead."

According to Avalanche Canada, five people have died in avalanches so far this year.