Avalanche Forecast

Issued: Dec 5th, 2021 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

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Choose terrain sheltered from the wind, and avoid thin, rocky start zones. Right now, wind slabs are the common problem, but triggering a high consequence, deep slab avalanche is possible. 

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

Sunday Night: Partly cloudy. Possible trace of snow. Light northwest wind. Alpine temperatures around -14

Monday: Scattered clouds, higher cloud rolling in over the day. No new snow expected. Variable light winds. Alpine low around -12 C, warming over the day, setting up a possible temperature inversion.

Tuesday: Overcast. 5-10 cm of snow expected. Strong to extreme southwest winds. Alpine temperatures above -10 C with possible temperature inversion.

Wednesday: Mostly cloudy. 0-5 cm of snow expected. Strong southwest winds. Alpine temperatures around -13. 

Avalanche Summary

A size 3 avalanche was reported in the Hankin-Evelyn area, failing near the ground. This has us thinking about the potential for a deep persistent weak layer.

This Mountain Information Network (MIN), post (and the two others pinned near it), paint a great picture of the current conditions at Hankin-Evelyn.

Reports in the region remain limited. A lack of information may not actually mean there is a lack of avalanche activity. 

Snowpack Summary

There are recent reports of large to very large avalanches running on or near the ground in the Bear Pass area and around Smithers. We don't know how widespread this problem may be, or if both events even reflect the same avalanche problem, but we are definitely keeping an eye on it, and would be avoiding large features and areas with thin to thick snowpack transitions for now. 

This snowpack summary is mostly speculative, as there is very little information in this region at the moment:) If you have been getting out in the backcountry, we'd love to see a photo or a quick story of your day posted to the Mountain Information Network. 

Due to recent, variable winds, you may find wind slabs on many aspects, and on both sides of ridges. Some exposed areas may be stripped back to the Nov 30/Dec 1 Crust. This crust has been reported up to 1600 m in the south end of the region.

The mid snowpack may be in a state of confusion at the moment. There may be moist snow under the Nov 30/Dec 1 Crust. The snowpack was previously expected to be gaining strength with consistent new snow load and warm temperatures, but recent cold temperatures are likely promoting faceting, especially around crusts.

Treeline snow depths are estimated to be 100-150 cm.

Terrain and Travel

  • Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
  • Avoid lee and cross-loaded slopes at and above treeline.
  • Keep in mind the crust offers an excellent bed surface for avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

Yesterday's forecaster blog does a great job of capturing the challenging travel and decision making we'll likely encounter in the backcountry right now. 

Wind slab avalanches may still be triggered by riders.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Avoid large features, and thin rocky start zones. Information is still being gathered about this potential weak layer near the bottom of the snowpack. 

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2.5 - 4

Valid until: Dec 6th, 2021 4:00PM

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