Avalanche Forecast

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack. Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.

Wednesday night: Scattered clouds, no new snow expected, light to moderate southwest winds trending westerly at higher elevations, alpine temperatures near -13 C.

Thursday: Partly cloudy, a trace of snow possible, light to moderate southwest winds trending westerly with strong gusts at higher elevations, alpine high temperatures near -8 C.

Friday: Mostly clear, up to 5 cm of snow expected overnight, light west winds increasing to moderate at higher elevations, alpine high temperatures near -11 C.

Saturday: Partly cloudy, up to 5 cm of new snow, southwest winds increasing to moderate with strong to extreme westerly winds in the alpine, alpine high temperatures near -5 C.  

It may be possible to trigger slab avalanches in wind-drifted areas at upper elevations or where a slab overlies weak snow on a crust. 

Over the last two day, operators have reported several large (size 2) explosive-triggered avalanche releasing on the early December crust layer. 

Observations from last weekend indicated that the snowpack was quite touchy. Avalanche control with explosives and ski cuts produced several size 2 avalanches, and one size 3. Most failed on top of the rain crust from the late November/early December rain events.

Up to 20 cm of snow has accumulated since Monday with very little wind. This fresh snow likely remains unconsolidated, except where the wind is drifting it into denser slabs at upper elevations. 

Below this layer, more consolidated snow from the previous weekend storm sits over a substantial crust that formed in early December. This crust is likely 20 cm thick (or more) and is present across aspects below 2400m. A thin layer of weak facets (sugary snow) can found above this crust that has demonstrated reactivity in snowpack tests and avalanche activity. 

Snowpack depths vary due to strong to extreme southwest winds from early December that stripped snow off of exposed areas and deposited it onto lee slopes. Below 2300m, several early season crusts are breaking down and forming a cohesive lower snowpack. Snowpack depths range from 60-110 cm at treeline elevations and taper quickly below 1900m.

• Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
• Make observations and assess conditions continually as you travel.
• Be aware of the potential for large avalanches due to the presence of a persistent slab.
• Uncertainty is best managed through conservative terrain choices at this time.