Avalanche Forecast

Issued: Dec 10th, 2018 5:13PM

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

Avalanche Canada jfloyer, Avalanche Canada

Snow amounts should remain light on Tuesday. If more than 15 cm new snow arrives, bump danger to Considerable for windy areas.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

Monday Night: Only trace amounts of new snow expected overnight.Tuesday: 4-8 cm new snow expected with moderate southwesterly winds. Freezing level rising to around 600 m at the end of the day. A further 10-20 cm possible Tuesday night. Wednesday: Flurries. Moderate northwesterly winds. Freezing level around 1200 m.Thursday: Light snow, 2-4 cm. Strong southwesterly winds. Freezing level rising to around 1400 m.

Avalanche Summary

Recent avalanche activity has been limited to a few small wind slabs and loose dry avalanches, mostly in steep alpine terrain.The last notable avalanche was a size 2 human triggered avalanche on December 2nd in Cornice Bowl north of Fernie. It occurred on a northwest facing feature at 2300 m and ran on a crust layer. There are good photos in this MIN report.

Snowpack Summary

Early season conditions prevail in this region with roughly 100 cm of snow in alpine areas and much less at lower elevations. Surface conditions range from soft power, to hard wind slab, and some sun crusts.See the snow profile in our field team's MIN report for a visual representation of the snowpack here. The main concern is a combination of weak facets and crusts in the bottom half of the snowpack. The crust is most prevalent at and above treeline and is likely most problematic on north-facing features, especially those that are large and planar in nature. A layer of large surface hoar can also be found at similar depths in some areas, as found in a recent MIN report here.

Problems

Wind Slabs

An icon showing Wind Slabs
Strong wind will transport loose snow and potentially form reactive slabs in the alpine. Wind slabs have the potential for wide propagations if they step down to the weak snow in the lower snowpack.
If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Be alert to conditions that change with elevation, aspect and exposure to wind.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Dec 11th, 2018 2:00PM