Avalanche Forecast
Issued: Jan 28th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
dsaly,
Avalanche Canada
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 the latest Forecaster Blog.
Summary
Confidence
Avalanche Summary
A Thursday report identified a size 2.5 avalanche on a northeast slope, triggered by a cornice failure.
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
Wind at upper elevations continues to impact flurries and older snow, 5 cm recent flurries covers a crust up to 1600 m. 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 problematic in steep, rocky alpine terrain, where shallower wind slab avalanches can scrub down to these basal facets.
Weather Summary
Saturday night
Clear and with gusty ridgetop winds. Ridge wind northwest reaching 50 km/hr. Alpine temperature -26 C.
Sunday
Sunny in the morning with increasing clouds throughout the day. Ridge wind northwest 20-40 km/hr. Alpine temperature -20 C.
MondayIncreasing cloud. Ridge wind west 30-50 km/hr. Alpine temperature -18 C.
TuesdayFlurries, 5 cm. Ridge wind northwest 30-40 km/hr. Alpine temperatures rising to -14 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.
Problems
Wind Slabs
Recent northwesterly winds have redistributed recent snow and pressed surfaces. Expected continued transport and new slabs where wind impacts loose snow.
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
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
Expected Size
Valid until: Jan 29th, 2023 4:00PM
