Avalanche Forecast

Issued: Dec 25th, 2015 4:50PM

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

Conrad Janzen, Parks Canada

Banff Yoho Kootenay.

Boxing Day specials on great skiing and Low hazard!Continue to evaluate steep alpine terrain for small wind slabs that are beginning to form.

Summary

Weather Forecast

A high pressure system continues to hold bringing cool and stable weather with no new snow in the forecast until at least the 27th. Upper elevation Westerly winds will increase through Saturday. Tree line temperatures should stay between -10 and -16'C.

Snowpack Summary

A well settled snowpack with few weaknesses exists throughout the region. Some small isolated wind slabs exist on leeward slopes in the high alpine. Below 2000m the Dec 3 layer of surface hoar remains visible and produces hard, planar test results in some areas. This weakness is strengthening. Thin snow pack areas are beginning to facet out.

Avalanche Summary

One new natural slab avalanche was observed on a steep N facing hanging snowfield on White Pyramid, 15-20m wide and about 1m deep, possibly cornice triggered. Some sluffing has been observed in really steep terrain due to the increasing winds moving the low density surface snow .

Confidence

Due to the number and quality of field observations

Problems

Wind Slabs

Some thin, isolated winds slabs are beginning to form in leeward areas near ridge crests as the winds increase. Keep an eye out for these spots when entering steep terrain.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Use safe ski cutting techniques before entering ski run.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

The slab above the Dec 3 surface hoar layer has not been very reactive recently. Snow pack tests produce shears in the moderate to hard range. This is mostly a concern in areas near the divide with a deeper snowpack and more snow over the weakness.

Dig down to find and test weak layers before committing to a line.Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.

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

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 2

Valid until: Dec 26th, 2015 4:00PM