Avalanche Forecast

Issued: Dec 18th, 2017 4:18PM

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

Avalanche Canada mbender, Avalanche Canada

Snowfall amounts over the weekend varied significantly. Ratings are based on higher amounts which seem to be south of Valemount.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

TUESDAY: Mix of sun and cloud, wind light to moderate northeast, alpine temperature -10 WEDNESDAY: Mix of sun and cloud, wind light north, alpine temperatures -11 THURSDAY: Cloudy with sunny breaks and isolated flurries, wind light to moderate north, alpine temperature -9 

Avalanche Summary

No new avalanches were reported within this region over the past few days. That being said as the recent new snow sitting on top of a variety of weak layers starts to settle, expect avalanche activity to increase. If you have any observations, please submit them to the Mountain Information Network (MIN).

Snowpack Summary

20-40cm of new snow accumulating through the weekend sits on a wide variety of old surfaces including large surface hoar (weak, feather-like crystals), hard crusts formed by sun or wind, and sugary facets. As the snow load builds and slab properties develop, it will be important to monitor how the new snow is bonding to the old surfaces. Most concerning would be areas that have surface hoar sitting on top of a hard crust. A crust which was formed by rain in late November is a major feature in the snowpack and is down approximately 60-80cm at tree line elevations. Snowpack tests suggest the snow above is currently bonding well to it. Snowpack depth decreases rapidly below tree line. Look out for early season hazards such as rocks, stumps, and open creeks.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent west and northwest winds have created wind slabs in the lee of terrain features.
Be cautious as you transition into wind affected terrain.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Storm Slabs

An icon showing Storm Slabs
As new snow accumulates and settles expect it to become reactive to human triggering. This new snow may be sitting on a weak layer of feathery surface hoar crystals especially in sheltered areas between 1600 and 2000m.
Buried surface hoar may be preserved on open slopes and convex rolls at and below tree lineWatch for whumpfing, shooting cracks, or signs of recent natural avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 19th, 2017 2:00PM