Avalanche Forecast

Issued: Nov 27th, 2019 4:00PM

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

Avalanche Canada astclair, Avalanche Canada

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Clear, cold, and dry weather is forecast for Thursday. The potential to trigger wind slabs lingers in the alpine.

Summary

Confidence

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

Weather Forecast

Wednesday night: Mostly clear skies, alpine temperatures -18 C, strong east/northeast winds, no significant precipitation expected.

Thursday: Mostly sunny, alpine temperature -15 C, light easterly wind, no precipitation.

Friday: Mostly sunny, alpine temperature -10 C, light easterly wind, no precipitation.

Saturday: Mostly sunny, alpine temperature -8 C, light variable wind, no precipitation.

Avalanche Summary

Observations are limited this time of year, so there is a fair bit of uncertainty about the extent of current avalanche activity. This small, skier-triggered avalanche was reported Monday following the weekend storm. The most likely place to trigger avalanches right now is where the wind previously drifted snow into wind slabs. If you see anything while out in the field, please consider sharing that information with us and the backcountry community via the Mountain Information Network.

Snowpack Summary

Snow line sits around 1200 m, and snow depths range from 90-140 cm at treeline elevations.

With this week's clear, cold, and dry weather, the weekend storm snow is likely losing strength, except where it has been drifted into wind slabs in the alpine. Variable winds have redistributed the 20-30 cm of recent snow into wind slabs that may still be possible to trigger. In some areas, this snow sits on a crust with surface hoar (feathery crystals). This "Nov. 23 crust" has produced repeatable sudden or propagating results in snowpack tests.  

A variety of crusts from late October are buried deeper in the snowpack (down 60 to 100 cm). The inactive weather pattern this week also promotes a decreasing trend in reactivity for these layers.

Problems

Wind Slabs

An icon showing Wind Slabs

Since the weekend storm, strong and variable winds have redistributed the 20-30 cm of snow into cohesive slabs that may still be possible to trigger in the alpine. 

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Nov 28th, 2019 5:00PM