Avalanche Forecast
Issued: Jan 22nd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Cornices.
ahanna,
Avalanche Canada
It is generally a good travel habit to minimize exposure to slopes with cornices overhead and stay well back of them when travelling on ridges. And it's an especially good idea on days like Saturday, when cornices are big and solar radiation is strong.
Summary
Confidence
High -
Weather Forecast
Friday night: Clear, light wind, alpine temperature -3, freezing level valley bottom.
Saturday: Sunny, light wind increasing to moderate northwest in the evening, alpine high -4 and cooling, freezing level valley bottom.
Sunday: Flurries up to 5 cm, light west wind, alpine high -9, freezing level valley bottom.
Monday: Flurries up to 10 cm, light northeast wind, alpine high -11, freezing level valley bottom.
Avalanche Summary
Explosive control work targeting cornices on Thursday produced size 1.5 results and did not trigger slabs in the slopes below. This indicates an improvement in stability since last weekend, when similar work produced size 2 results, some triggering deep slabs on the rocky slopes below.Â
Earlier this month, we saw significant deep persistent slab activity, both natural and human triggered. Deep glide cracks have also been observed previously but appear to be holding together in the cool temperatures.
Snowpack Summary
Extensive wind effect in the alpine includes scoured windward aspects and hard slabs in lee terrain. As wind slabs facet and lose cohesion in the cold temperatures, they have become largely unreactive. A widespread surface crust exists below 1900 m and on south-facing slopes.
Remnants of a melt-freeze crust from early December may be found around 200 cm deep in the snowpack. In thin rocky snowpack spots, it still shows some propagation and collapse to moderate to hard loading in the most recent snowpack tests. In thicker snowpack areas it has shown no results, and appears to be trending dormant... for now at least.
Terrain and Travel
- Minimize your exposure time below cornices.
- Cornices become weak with daytime heating or solar exposure.
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
Problems
Cornices
Cornices may weaken with prolonged exposure to direct sun. Minimize exposure to overhead hazard when solar radiation is strong. A few recent cornice falls have triggered wind slabs on the slopes below.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Jan 23rd, 2021 4:00PM
