Avalanche Forecast

Issued: Jan 21st, 2021 4:00PM

The alpine rating is low, the treeline rating is low, and the below treeline rating is low. Known problems include Cornices and Wind Slabs.

Avalanche Canada ahanna, Avalanche Canada

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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 -11.

Friday: Sunny, light wind, alpine high -9.

Saturday: Sunny with increasing cloud in the afternoon, light wind, alpine high -9.

Sunday: Flurries, up to 5 cm, light wind, alpine high -10.

Avalanche Summary

No new reports in the last day. Earlier in the week, reports from the northern part of the region included a natural wind slab avalanche size 1.5 at treeline and a few cornice falls up to size 2. Some of the cornice falls triggered wind slab avalanches up to size 2 in the slopes below. None of these large loads triggered deep persistent layers.

Snowpack Summary

In the south of the region, fluctuating freezing levels during the last storm have resulted in a crust to ridgecrest. At upper elevations, 5-10 cm of dry snow has been blown around by the wind, exposing the crust in some areas and building wind slabs on top of it in others. The lower snowpack is well settled.

In the north, upper elevations are extensively wind affected. A widespread surface crust exists below 1600 m. Remnants of a melt-freeze crust from early December may be found around 200 cm deep in the snowpack. It has been most prevalent northwest of Pemberton where large avalanches failed on this interface earlier this month. Recent reports and snow profiles suggest that this layer is decomposing and/or bonding to surrounding snow and 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

An icon showing 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

Unlikely - Possible

Expected Size

1.5 - 2.5

Wind Slabs

An icon showing 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

Unlikely - Possible

Expected Size

1 - 2

Valid until: Jan 22nd, 2021 4:00PM