Avalanche season in B.C. forecast to be the most dangerous in decades

NORTH VANCOUVER, B.C. -

Forecasters are warning outdoor enthusiasts to beware of the backcountry as British Columbia is expected to have a particularly dangerous avalanche season.

“This year’s snowpack is different from most previous years,” wrote Mike Conlan, an avalanche forecaster for Avalanche Canada.

Experts say the snowpack only gets this weak every 10 to 20 years.

They’re comparing it to what B.C. saw back in 2003, which was one of the deadliest avalanche seasons on record.

“This winter presents a very different set of problems than normal and we need to adjust our mindset to remain safe,” wrote Conlan.

The current conditions were created by lengthy periods of drought and cold weather last year. The rain and snow recorded over the last few weeks has created “problematic layers” in the snowpack.

“It's actually more of it looks more like a snowpack we would get in April, like a spring condition,” said André-Jean Maheu, an avalanche forecaster for North Shore Rescue.

Snow and wind early this week are expected to form fresh storm slabs, which are susceptible to being triggered by humans.

Experts are warning those spending time in the backcountry to stick to slope angles less than 30 degrees when in clearings, open trees, and alpine terrain.

Avoid gullies, cliffs, and trees to reduce the consequence of being caught in an avalanche.

“If we had to summarize the message that we're trying to bring right now, it would be restraint and discipline, which doesn't sell very well, I have to say, with skiers and snowboarders and people who recreate in the backcountry. But that's definitely it,” said Maheu.

Avalanches can be triggered from a distance because the buried weak layers are widespread and spatially connected.

That can make it difficult to anticipate where avalanches may be triggered from.

The weak layers may also be hard to detect.

“The complication with this snowpack setup is that the layers are deep enough that we are a lot less likely to see clues, like nearby avalanche activity, whumpfing, or cracking snow,” wrote Conlan.

Avalanche Canada also warns that many avalanches are triggered where the layers are shallowly buried

“Triggering is less likely when weak layers are buried deeper than about a metre because our stresses are absorbed by the upper snowpack,” explained Conlan.

A triggered avalanche in these conditions will likely Size 2 (large) or Size 3 (very large) on Avalanche Canada’s scale.

The weak snowpack is expected to linger around for a while, possible even the entire season.

The layers could take months to shrink and bond, meaning avalanches may continue into early summer in the high alpine.

The majority of B.C. is at a two or three out of five on the Avalanche Danger Scale.

The risk in alpine areas is considered “considerable,” meaning there are dangerous avalanche conditions.

“This is unfortunately typically the hazard rating where we see the most avalanches. When the hazard goes to high, people usually step back. When the hazard is considerable, people have a tendency to still want to go out a little bit,” said Maheu.

Maheu says it’s been a relatively quiet start to the rescue season so far because the weather has not been ideal, but he’s warning people not to be complacent.

“We've seen through the province recently some very significant close calls with people triggering very large avalanches and very narrowly escaping,” said Maheu.

He’s encouraging everyone spending time in the back country to be equipped with an avalanche transceiver, probe and shovel.

“It shouldn't be considered an option to say, ‘Oh, well, we can go on that slope because we have all the rescue equipment.’ That would be the equivalent of driving recklessly because you have an airbag in your car,” said Maheu.