Avalanche Forecast
Issued: Jan 21st, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Cornices and Wind Slabs.
ahanna,
Avalanche Canada
Even with compact snow surfaces and cool temperatures, don't underestimate the power of the sun. Minimize exposure to slopes with cornices overhead when solar radiation is strong. Wind slabs are stubborn to trigger but a large load like a cornice fall might do it.
Summary
Confidence
Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.
Weather Forecast
Thursday night: Clear, light wind, alpine low -8, freezing level valley bottom.
Friday: Sunny, light wind, alpine high -4, freezing level 500 m.
Saturday: Sunny with increasing cloud in the afternoon, light wind increasing to moderate northwest, alpine high -7, freezing level valley bottom.
Sunday: Flurries up to 5 cm, light wind, alpine high -9, freezing level valley bottom.
Avalanche Summary
No new reports in the last couple days. A few small wind slab avalanches were reported early in the week. Explosive control targeting cornices on Friday and Saturday 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.
Snowpack Summary
Extensive wind effect in the alpine includes scoured windward aspects and hard slabs in lee terrain. Soft snow may be found in sheltered areas around treeline. 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. Several large natural and human triggered avalanches failed on this layer earlier this month. Although it still shows propagation and collapse to moderate to hard loading in the most recent snowpack tests, it has become well bridged by overlying snow and crust.
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 avalanches on the slopes below.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Old wind slabs in isolated terrain features have likely become stubborn to trigger. Large loads like cornice falls could still trigger avalanches on wind loaded slopes below.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 22nd, 2021 4:00PM
