Avalanche Forecast

Issued: Dec 10th, 2020 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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Avalanche hazard may be low but do consider your knees. Travel conditions may be difficult with minimal snow coverage at lower elevations and where the crust is punchy and unsupportive.

Summary

Confidence

Moderate - Uncertainty is due to limitations in the field data.

Weather Forecast

Thursday night: Isolated flurries, light southeast ridgetop wind, freezing level 600 m.

Friday: Isolated flurries with sunny breaks, light variable ridgetop wind, alpine high temperature -6C, freezing level 900 m

Saturday: Sunny with increasing afternoon cloud, light variable ridgetop wind, alpine high -2C, freezing level 700 m.

Sunday: Up to 10 cm new snow, light to moderate southwest wind, alpine high -6C, freezing level 700 m.

Avalanche Summary

By Wednesday, the recent storm snow appeared to have locked up, as explosive control work produced only limited size 1 loose dry results in the low density surface snow over the crust.

A widespread natural cycle occurred during the storm Monday night through Tuesday, storm slabs size 2-3 and loose wet size 1-2.

Have you been out and about in the mountains? If so please submit your observations to the Mountain Information Network (MIN). It doesn't have to be technical - photos are especially helpful! Thank you so much for all the great MINs submitted so far! 

Snowpack Summary

5-10 cm of dry snow sits over a robust crust that formed at all elevations during the warm, wet storm earlier this week. 

At treeline and below, the crust continues to harden with cool temperatures but may still be somewhat punchy, with a saturated snowpack below.

In the alpine, the crust is supportive. Sugary facets sit sandwiched between this surface crust ontop, and an ice lens up to 50 cm below the surface. The ice lens formed from the freezing rain that fell on the old snow surface at the beginning of the previous storm. Above 2100 m, it has been a failure plane for avalanches since the storm.

Snowpack depths change rapidly with elevation, from 50-100 cm around treeline to over 150 cm in the alpine.

Terrain and Travel

  • A crust on the surface will help bind the snow together, but may make for tough travel conditions.
  • Be alert to conditions that change with elevation.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.

Problems

Storm Slabs

An icon showing Storm Slabs

Keep a look out for lingering slabs around steep rolls and extreme terrain. Cornices might still be a bit touchy.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Dec 11th, 2020 4:00PM