Wind slabs and cornices in the alpine are front of mind. Avoiding thin rocky areas will help manage the lingering deep instabilities. The best conditions will remain in the most sheltered areas.
Recent winds have hammered the surface at wind-exposed elevations. Wind slabs may be found unusually low in start zones due to recent strong winds on all aspects.
Cornices have seen significant growth recently. Give them a wide berth whether travelling on or below ridgelines. Cornices can be dangerous on their own and they can also act as large triggers to deep slab avalanches on slopes below.
Weak, sugary crystals at the bottom of the snowpack have produced large avalanches recently. These avalanches are most likely to be triggered by large loads such as cornice falls. But they can also be triggered by the weight of a person from shallow snowpack areas, and propagate out to deeper snow resulting in large, destructive avalanches.
Our field team continues to observe numerous natural wind slab avalanches up to size 2.
Last week, several large deep persistent slab avalanches were reported in the alpine, including a natural size 3 near Kispiox, a cornice-triggered size 2.5 at Hudson Bay and several explosive controlled size 2-3 near Ningunsaw.
Extensive wind effect characterizes the snow surface at upper elevations. Exposed windward aspects have been scoured. Wind slabs may be found sitting unusually low down in start zones and lees.
In sheltered areas, 40-50 cm of recent snow may be sitting over a layer of small facets and cold snow that feels upside down
Several other crusts, layers of facets, or surface hoar can be found in the top 150 cm of the snowpack, but have not shown any avalanche activity or tests results yet.
The lower snowpack consists of weak, basal facets which may become active with any rapid change or shock to the snowpack, such as heavy loading or dramatic warming. Snowpack depths range from 60 to 280 cm at treeline.
Friday night
Flurries. Moderate southerly wind. Alpine low -10 ºC.
Saturday
Mostly cloudy. Possible flurries. Moderate becoming light southeasterly wind. Alpine high -8 ºC.
Sunday
Mostly cloudy. Possible flurries. Moderate southeasterly wind. Alpine high -15 ºC.
Monday
Mostly cloudy. Southwesterly wind increasing, with alpine winds up to 40 km/h. Alpine high -15 ºC.
More details can be found in the Mountain Weather Forecast.
