Avalanche Forecast

Sunday night: Mostly cloudy, scattered flurries with up to 5 cm of snow above 1200 m, moderate southwest winds, freezing level dropping to 1200 m.

Monday: Mostly cloudy, 5-10 cm of snow above 1200 m, moderate southwest winds, freezing level near 1200 m.

Tuesday: Partly cloudy, scattered flurries with up to 5 cm of snow, light to moderate southwest winds, freezing level dropping to 500 m.

Wednesday: Partly cloudy, light northwest winds, isolated flurries with trace accumulations, alpine high temperature -4 C.

 During the weekend storm, professional operators reported small to large (size 1-2) natural and explosive-triggered wind slabs on northwest, north, and northeast aspects in immediate lee features. During peak warming, a widespread cycle of small loose wet avalanches was observed up to 1800 m. Shallow slabs in the new snow may be possible to trigger in wind-loaded steep, rocky, or convex features near ridge crests and roll-overs. See this MIN report for a great example. 

Outside of the region near Tatlatui Provincial Park on Friday, operators triggered two large (size 2) avalanches with explosives that released on weak snow at the ground. Earlier in the week, a series of very large (size 3-3.5) natural deep persistent slab avalanches were reported near Ningunsaw that also failed on weak snow at the ground. 

Our eyes and ears in the mountains are limited this winter due to fewer professional observations. If you go out in the mountains, please share your observations on the Mountain Information Network (MIN). Photos are especially helpful! 

The weekend storm brought varying accumulations of snow followed by rain up to mountain top elevations. In many treeline and belowtreeline areas, the combination of above freezing temperatures and rain saturated the entire snowpack. As a result, snow has melted fast at lower elevations, and snowpack depths have seen rapid settlement. 

As the freezing level gradually drops below 1000 m by end of day Monday, a widespread melt-freeze crust will be left behind across aspects and elevations. Ongoing southwest winds are expected to drift 5-15 cm of new snow into wind slabs on lee and cross-loaded features in the alpine or in "alpine-like" features at treeline. Where snow accumulates over the recently formed melt-freeze crust, shallow slabs may be possible to trigger. 

In areas north and east in the region, the bottom half of the snowpack reportedly consists of weak snow interrupted by a crust from early November. These weak layers have produced very large deep persistent slab avalanches near the Ningunsaw and Tatlatui Provincial Parks. The extent of this snowpack structure in the region is not well-known. Smaller avalanches in the new snow may have the potential to step-down to deeper layers and to produce large, destructive avalanches. Large alpine slopes where the snow transitions from thick to thin are most suspect. 

Snowpack depths vary substantially with aspect, elevation, and wind exposure (check out this MIN report for a great visual). Lower elevation terrain may still be below the threshold for avalanches. 

• Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
• Avoid freshly wind loaded terrain features.
• Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.