Avalanche Forecast

Issued: Dec 9th, 2018 5:30PM

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

Avalanche Canada cgarritty, Avalanche Canada

Conditions are finally in transition. New snow will accumulate throughout the week, but forecast strong alpine winds are the critical factor for avalanche danger on Monday.

Summary

Confidence

High -

Weather Forecast

Sunday night: Cloudy with scattered flurries bringing a trace to 5cm of new snow. Moderate to strong southwest winds.Monday: Cloudy with diminishing flurries and a trace of new snow. Light to moderate southwest winds, increasing overnight. Alpine high temperatures around -8.Tuesday: Cloudy with flurries bringing about 5 cm of new snow, increasing overnight. Strong to extreme south winds. Alpine high temperatures around -8.Wednesday: Cloudy with scattered flurries with 2-5 cm of new snow, continuing overnight. Strong west winds. Alpine high temperatures around -9.

Avalanche Summary

No new avalanches have been reported.

Snowpack Summary

Increasing south winds and light new snow amounts have likely begun forming new wind slabs on north aspects. Beneath the surface, the snowpack is currently quite stable in most places, however a buried weak layer still exists down 20-60 cm. This layer consists of a sun crust on steep south facing slopes, and/or weak surface hoar crystals on more shaded and sheltered slopes. The surface hoar is most prominent at treeline. Although it is slowly healing into the snowpack, it may still react to triggers in areas where surface hoar is sitting on the crust. This combination is most likely found on steep south facing terrain at treeline.At the base of the snowpack is a crust that formed in late October. The probability of triggering this layer is low, but the most suspect areas would be large, steep, rocky alpine features with a shallow snowpack. It would likely take a large trigger such as a cornice fall to produce an avalanche on this layer.Snowpack depths decrease dramatically with elevation.The VARDA gang produced a great video from the Allan Creek zone near Valemount, click here to check it out.

Problems

Wind Slabs

An icon showing Wind Slabs
Strong southwest winds and light new snow amounts are expected to form thin new wind slabs in the alpine. Wind slabs are smooth, rounded, lens/pillow shaped formations of snow with a chalky consistency that often feels stiff under tracks and skis.
Watch for newly formed wind slabs on leeward slopes as you transition into wind affected terrain.Expect thicker, touchier slabs in the immediate lee of ridgecrests and other wind-exposed features.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 1.5

Valid until: Dec 10th, 2018 2:00PM

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