Heads up hockey! Despite benign weather, a buried weak layer is becoming more unstable. Large human-triggered avalanches are likely. These dangerous conditions warrant careful assessment and wide terrain margins. Get the details in our forecaster's blog here.
Recent winds have varied in direction and wind slabs may be found on multiple aspects. North winds may have created a tricky reverse-loading pattern. Avoid slopes where the snow feels stiff or "slabby," and seek out softer conditions in wind-sheltered terrain.
A layer of weak facets (sugary snow) can be found down 50-100 cm near a crust layer that formed in early December. As the snow consolidates over this weak layer, the likelihood of human-triggering large, destructive avalanches is increasing. Multiple recent reports of large remote-triggered avalanches on this layer in the north of the region warrant vigilant, conservative terrain margins.
Thursday night: Clearing overnight, no new snow expected, light west winds, low treeline temperatures near -16 C, freezing level at valley bottom.
Friday: Increasing cloudiness, no new snow expected, moderate southwest winds, high treeline temperatures near -10 C.
Saturday: Overcast, 5-10 cm of snow accumulating by the end of the day, strong southwest winds, treeline temperatures rising to -3 C and freezing level rising to 500 m by late afternoon.
Sunday: Cloudy, up to 5 cm of snow, light variable winds, high treeline temperatures -6 C, freezing level around 200 m.
The likelihood of human-triggering large, destructive avalanches is increasing. An operator in the north of the region on Thursday observed a widespread, large natural avalanche cycle, releasing on the persistent weak layer on southerly aspects at upper elevations. In the neighbouring Sea-to-Sky region, we received reports of two large (size 2-3) persistent slab avalanches on northwest and southwest aspects between 1700-1900 m. Notably, skiers remote-triggered these avalanches while traveling uphill. Several small (size 1-1.5) sympathetic avalanches also released on nearby terrain features during these close calls.
On Wednesday, small to large avalanches in the recent storm snow were triggered with explosives.
We have few observations from the south of the region. Check out this recent MIN report of a naturally triggered size 3.5 storm slab avalanche reported last Sunday near Mt. Pierce.
Winds shifted to the north on Thursday and may have created a tricky reverse-loading pattern. Avoid slopes where the snow feels stiff or slabby, and seek out softer conditions in wind-sheltered terrain.
The primary layer of concern is a weak layer of facets (sugary snow) above a widespread crust down 50-100 cm that formed in early December. On Thursday, this persistent slab problem produced a natural avalanche cycle in the north of the region and surprised several recreationists in the neighbouring Sea-to-Sky region with large, remotely-triggered avalanches. This problem is particularly hard to predict, tricky to manage, and will likely continue to surprise complacent backcountry travelers. Given recent natural, remote-triggered, and sympathetic avalanche activity, these conditions require wide, conservative terrain margins and disciplined backcountry travel techniques.
