Avalanche Forecast

Issued: Feb 25th, 2016 8:29AM

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

Avalanche Canada pgoddard, Avalanche Canada

New snow and strong winds are expected to continue adding to the widespread wind slab problem.

Summary

Confidence

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

Weather Forecast

The first of two cold fronts is expected to bring 10-15 cm snow on Friday, with strong southerly winds and the freezing level rising to around 1200 m. There is a lull on Saturday before the second front brings around 15 cm and more strong winds on Sunday.

Avalanche Summary

Size 1-2 wind slabs were triggered naturally and by skiers on Wednesday, mostly at alpine and treeline elevations.

Snowpack Summary

Recent strong winds have created wind slabs on a variety of slopes at alpine and treeline elevations. Incoming snow will bury a thin sun crust on sunny aspects and surface hoar in isolated sheltered and shady locations. 40-100 cm of snow sits above a melt freeze crust buried around February 12th. This crust extends up to about 2000 m. Although the snow above is bonding well to this crust in most places, recent snow pit tests northwest of Terrace produced failures on or in facets just below this layer under moderate to hard loads. Below this, a layer of surface hoar buried late in January remains a concern in thin snowpack areas in the east and north of the region. The snowpack in these areas may also sit on a weak base of facets near the ground. Below treeline, the snowpack depth is lean to non-existent in the south. In the north, the below treeline snowpack is generally considered strong.

Problems

Wind Slabs

An icon showing Wind Slabs
Recently formed wind slabs are lurking on many alpine and treeline slopes. Incoming snow, wind and rising temperatures may create a new storm slab problem above older wind slabs.
Choose well supported terrain without convexities.>Be alert to conditions that change with aspect and elevation. >Travel on ridgetops to avoid wind slabs on slopes below.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
A storm slab or wind slab could step down and trigger a deeply buried weak layer, creating a surprisingly large avalanche.
Dig down to find and test weak layers before committing to a big line. >Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Feb 26th, 2016 2:00PM