Avalanche Forecast

Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

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.

• Be aware of the potential for large avalanches due to the presence of a persistent slab.
• Remote triggering is a concern, avoid terrain where triggering slopes from below is possible
• Uncertainty is best managed through conservative terrain choices at this time.
• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.