Avalanche Forecast

Issued: Dec 16th, 2016 3:54PM

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

Avalanche Canada swerner, Avalanche Canada

Winds will be cranking through the weekend! New wind slabs may be easily triggered by a skier or snowmobiler.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

The dominating Arctic high slides south allowing a series of Pacific frontal systems to cross the Interior through the forecast period. Strong ridgetop winds will crank up Saturday accompanied by new snow and slightly warmer temperatures Sunday and onward.Saturday: Alpine temperatures -20, ridgetop winds from the West 20-30 km/hr.Sunday: Alpine temperatures -15, ridgetop winds West 50-60 km/h, trace of new snow.Monday: Alpine temperatures -7, ridgetop winds SW 40-80 km/h, snow 15-20 cm.

Avalanche Summary

Recent reports from Thursday indicated natural cornice and ice falls from 2300 m and above on NW and SW aspects, triggering either a small wind slab or entraining surface snow on the slopes below. Loose dry sluffing from steeper terrain may push you off your line, so watch and avoid terrain traps below. With forecast strong winds over the weekend, wind slab problems may increase and be triggered by light loads (skiers/ sledders).

Snowpack Summary

Recent wind has formed wind slabs on a variety of aspects in the alpine. The cold temperatures and clear skies are developing facets near the surface and new surface hoar growth in sheltered locations. There may be a layer of surface hoar buried 20-30 cm deep in sheltered areas, especially in the Dogtooth Range. Alpine snow depths are around 120-170 cm, and the widespread mid-November crust is buried down around 70-90 cm. In shallower snowpack areas reports indicate that the bond to the crust is weakening and something to keep track of. Snowpack and crust depths increase as you move west toward the Selkirk Range. If you dig down to the crust, watch for facets (sugary crystals) developing above and below. This may provide a hard surface with a weak sliding layer in the future.

Problems

Wind Slabs

An icon showing Wind Slabs
Forecast strong winds may build new wind slabs. Watch for conditions that change with aspect and elevation.
Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 17th, 2016 2:00PM