Avalanche Forecast

Issued: Jan 18th, 2018 5:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

Be observant of wind effect as you transition to higher elevations. Expect storms slabs to be more reactive in wind affected terrain.

Summary

Confidence

Moderate -

Weather Forecast

Friday: Mainly cloudy. Light east winds. Alpine high temperatures to -3Saturday: Cloudy with scattered flurries bringing 2-5 cm of new snow. Light to moderate southeast winds. Alpine high temperatures to -5.Sunday: Cloudy with isolated flurries and a trace of new snow. Moderate east winds. Alpine high temperatures of -6.

Avalanche Summary

Reports from Thursday showed ski cutting producing loose wet releases to Size 1 in steep terrain in the Shames area. Several older Size 1.5 natural storm slab releases were also noted.  Looking forward, the storm slabs that formed over Thursday may remain reactive to human triggering on Friday. This concern will be greatest in wind affected areas at higher elevations.

Snowpack Summary

Snowfall over Wednesday and Thursday brought about 20 cm of new snow to the region. Moderate southwest winds over Thursday promoted storm slab formation at higher elevations and particularly in lee areas subject to wind loading. The new snow has buried a mix of old wind slabs and temperature crusts left over from the weekend. Professionals have been monitoring a few layers in the upper snowpack, including crusts and surface hoar layers buried 40-80 cm below the surface. Although these layers have been reactive in recent snowpack tests, they have not produced avalanches lately. The lower snowpack is generally strong, with the exception of areas around Stewart and further north where a basal crust and facets exist.

Problems

Storm Slabs

An icon showing Storm Slabs
Thursday's new snow and southwest winds formed fresh storm slabs. Slabs are likely to be touchiest in wind affected areas, and particularly in the immediate lee of ridgecrests and exposed terrain features.
Use ridges or ribs to avoid steep pockets of wind loaded snow.Use extra caution in lee areas. Slabs will be touchier where wind loading has occurred.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 19th, 2018 2:00PM