Avalanche Forecast

Issued: Dec 8th, 2018 3:51PM

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

Avalanche Canada ghelgeson, Avalanche Canada

Watch for the formation of wind slabs in the alpine Sunday as a strong southwest wind moves into the region.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

A storm impacts the coast Sunday which should start to erode the ridge of high pressure that has been plaguing the province for the last week. A bit of snow may venture into the region Sunday with potential for another wee storm Tuesday night into Wednesday. SATURDAY NIGHT: Freezing level at valley bottom, moderate southwest wind in the alpine, no significant precipitation expected.SUNDAY: Clear skies in the morning with steadily increasing cloud through the day, freezing level at valley bottom, strong southwest wind in the alpine, trace of precipitation possible during the day, potential for 1 to 5 cm of snow Sunday night.MONDAY: Broken cloud cover, freezing level at valley bottom, light to moderate southwest wind, trace of precipitation possible.TUESDAY: Overcast, freezing level starting near valley bottom rising to 1500 m during the day, strong to extreme southwest wind, 1 to 5 cm of snow possible during the day, potential for 4 to 10 cm of snow Tuesday night.

Avalanche Summary

No new avalanches have been reported.

Snowpack Summary

The VARDA gang produced a great video from the Allan Creek zone near Valemount, check it out here. 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 surface hoar (feathery crystals). The surface hoar is most prominent at treeline. The most likely place to trigger this layer is where the 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 likely 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.

Problems

Wind Slabs

An icon showing Wind Slabs
Strong southwest winds on Sunday may begin to form wind slabs in the alpine.  Wind slabs are often smooth, rounded, lens/pillow shaped formations of snow that can be chalky-white in color, and they often feel stiff under tracks and skis.
Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.Highmark or enter your line well below ridge crests to avoid wind loaded pillows.Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Dec 9th, 2018 2:00PM