Avalanche Forecast

Issued: Jan 24th, 2021 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

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Be ready to manage touchy wind new wind slabs on Monday. Dial back your terrain selection to account for a more widespread storm slab problem if we get surprised with more than 15 cm of new snow.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Sunday night: Continuing light flurries bringing up to 5 cm of new snow. Light southeast winds.

Monday: Continuing light flurries bringing up to 5 cm of new snow, continuing overnight. Light south or southeast winds. Alpine high temperatures around -10.

Tuesday: Mainly cloudy with 3-day new snow totals around 10-15 cm. Light to moderate southeast winds. Alpine high temperatures around -13.

Wednesday: Cloudy with isolated flurries and a trace of new snow. Light southeast winds. Alpine high temperatures around -12.

Avalanche Summary

No new avalanches have been reported in the last few days of stagnant weather and generally good stability. Looking forward, new surface instabilities are expected to form as light new snow amounts continue to accumulate. 

Initially problems are likely to take the form of small wind slabs in setting up in the immediate lee of exposed terrain features. This may expand to a more widespread storm slab problem in areas we see accumulations reach 15 or more cm.

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

Light new snow amounts have begun to accumulate over generally hard surfaces throughout the region; old stiff wind slab at upper elevations and a crust below 1900 m and on south aspects. In the recent cool, clear weather, crystals such as surface hoar and facets have formed on top of these old surfaces. This setup will become problematic anywhere enough new snow accumulates to form fresh wind slabs.

Remnants of a melt-freeze crust from early December may be found around 200 cm deep in the snowpack. In shallow 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, at least for now.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Light new snow amounts are accumulating above a range of weak surfaces that new snow won't bond well to. Only wind loaded pockets will likely see enough accumulation to pose a hazard on Monday, but expect them to be touchy to light triggers.

Aspects: North, North East, East, West, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Jan 25th, 2021 4:00PM