Sustained snowfall creates extreme avalanche risk in Interior B.C.

A prolonged bout of precipitation has lead to another weekend of extreme avalanche risk in Interior B.C.

Avalanche Canada's most recent forecast, issued Friday evening, lists almost the entire eastern half of the province at "high" avalanche risk the second-highest rating on its five-point scale.

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"Intense snowfall and strong wind will almost certainly initiate a very large and destructive natural avalanche cycle on Saturday," reads a warning on Avalanche Canada's website issued for the Cariboo, North Columbia, South Columbia, Kootenay and Purcell regions.

"Only the most simple avalanche terrain free of overhead hazard is appropriate at this time."

Avalanche risk is also listed as considerable for much of the rest of the province, including the South and North Coasts.

Avoid high-risk terrain, forecasters say

Colin Garritty, a forecaster with Avalanche Canada based in Revelstoke, said this weekend's elevated risk is due to a combination of new snow and existing unstable base layers from as far back as mid-December.

"These are anywhere from a metre to two metres below the surface, so it's not something you can see on the snow surface," he said.

Garritty expects the risk to remain high until at least mid-February, possibly longer. He said anyone planning any backcountry excursions should take extra care to avoid avalanche terrain.

"Even professionals in the industry, we're stepping back and we're choosing previously skied terrain and reducing exposure to large overhead avalanche terrain," he said.

"This is maybe a time to ... choose professional guidance, or to spend a great day at the ski hill, because we've been having amazing conditions in those areas where the avalanche danger is managed by professionals."

Mountain parks issue warnings

Parks Canada issued a similar warning for its mountain parks, including Jasper, Banff, Yoho, Kootenay and Glacier.

"We expect another natural avalanche cycle to occur starting Friday night and tapering off late on Saturday," reads Parks Canada's warning.

"Ski resorts and non-avalanche terrain are the places to enjoy the fresh snow right now."

Highway 1 will be closed in several places on Saturday to allow for avalanche control, according to DriveBC.

A 22-kilometre stretch east of Revelstoke will be closed mid-morning through early afternoon. Intermittent closures of up to three hours are expected throughout Glacier National Park, including Rogers Pass.