Avalanche Forecast
Regions: Pine Pass.
There is a lot of uncertainty with the reactivity of deeply buried weak layers. Conditions like this are best managed by sticking to lower-angle terrain away from any overhead hazard.
Read more in our latest forecaster blog.
Confidence
Moderate
Avalanche Summary
A Thursday report identified a size 2.5 avalanche on a northeast slope, likely triggered by a cornice failure. Ongoing wind slabs are expected with artic air redistributing available snow.
An ongoing concern for step-down and large natural and human-triggered deep persistent slab avalanches is at the forefront of our minds. Check out this video on incremental loading to learn more.
Please continue to send in your observations through the MIN.
Snowpack Summary
Previous warm temperatures have produced a crust up to 1600 m, at higher elevations northwest winds formed slabs in lee terrain.
Snowpack depths are shallower than normal, and several buried weak layers have been a concern over the past few weeks. Surface hoar or crust layers in the mid-snowpack may exist in this region, but field observations suggest these mid-snowpack weaknesses are less prominent here than in areas further south.
The most concerning layer in this area is at the base of the snowpack. Large, weak facets buried in November are widespread. This layer is most likely to be problematic in steep, rocky alpine terrain, where shallower wind slab avalanches can scrub down to these basal facets.
Weather Summary
Friday night
Cloudy with strong wind. Ridge wind northeast 40-60 km/hr. Alpine temperature -16 C. Artic air bringing cold temperatures and northerly outflow winds.
Saturday
Increasingly sunny and windy. Ridge wind northeast 30-50 km/hr. Alpine temperature -18 C.
SundaySunny. Ridge wind northeast 20-40 km/hr. Alpine temperature -20 C.
MondaySunny. Ridge wind northeast 20-40 km/hr. Alpine temperature -25 C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
- Uncertainty is best managed through conservative terrain choices at this time.
Avalanche Problems
Wind Slabs
Recent northwesterly winds have redistributed recent snow and pressed surfaces. Expected continued transport and new slabs where wind impacts loose snow. Northeast arctic outflow winds may reverse-load features and build slabs in less common areas.
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Deep Persistent Slabs
A layer of large and weak facets sits near the base of the snowpack. This layer has most recently been problematic in upper treeline/lower alpine elevations. Riders are most likely to trigger an avalanche on this layer in steep, shallow previously undisturbed terrain, or by first triggering a layer further up in the snowpack.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Unlikely - Possible
Expected Size: 2 - 3.5
