Avalanche Forecast
Issued: Dec 21st, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Dry and Deep Persistent Slabs.
Darren vonk,
The snowpack is currently adapting to a large load in a short period of time, As the sky's clear and the powder calls, keep your guard up and assess each slope with a critical eye and work through the terrain with a conservative approach.
Summary
Weather Forecast
A final pulse of snow (10cm) is expected tonight before tapering off for the holidays. Winds will continue to gust to 50km until Tuesday afternoon when the winds finally abate to light SW winds at ridge tops.
Tuesday and Wednesday will see a mix of sun and cloud with no precipitation expected
Snowpack Summary
Up to 50cm of low density storm snow over last few days. SW winds continue to build wind slabs in the alpine and treeline. Decomposing surface hoar down 30cm to 50cm in sheltered locations treeline and below. The midpack is generally supportive with a weaker base consisting of facets and depth hoar. Avg depth is 65cm - 160cm depending
Avalanche Summary
A field team in the Hilda area today noted no new avalanches. In test pits they were observing Resistent planner results in the storm snow only. In the alpine they observed good skiing in sheltered locations and found wind effected snow in proud and open area's with no reactivity.
Marmot had 1 Sz 2.5 wind slab out of steep Northerly cliffy terrain.
Confidence
Problems
Wind Slabs
New snow and strong to extreme winds are forming wind slabs on leeward and cross-loaded terrain features. Although we are not seeing a lot of avalanche activity with this problem, the weather has been perfect for wind slab development.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
- Use caution in alpine lee areas. Recent snow is available for transport given the current winds.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
New snow may be reactive on the Dec 14th layer and in steep terrain
- Be careful of loose dry power sluffing in steep terrain.
- Carefully assess open slopes at and below treeline where buried surface hoar may be preserved.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Be cautious of thick to thin snowpack areas being likely trigger locations. The new wind slabs forming have the potential to step down to the weakness at the base of the snowpack.
- Use caution in thin snowpack areas.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 22nd, 2020 4:00PM
