Avalanche Forecast

Issued: Dec 12th, 2018 5:05PM

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

Avalanche Canada cgarritty, Avalanche Canada

Storm snow is coming in gradually, but high elevation winds are likely making quick work of forming slabs with it.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

Wednesday night: Cloudy with increasing flurries bringing 5-10 cm of new snow. Strong to extreme southwest winds. Thursday: Mainly cloudy with easing flurries bringing a trace to 3 cm of new snow. Strong to extreme southwest winds. Alpine high temperatures around -9.Friday: Cloudy with another storm pulse bringing 5-10 cm of new snow. Mainly light northeast winds, increasing to strong in the alpine. Alpine high temperatures around -8.Saturday: Mainly cloudy with cloud increasing and flurries beginning in the evening. Light variable winds before increasing and becoming southeast. Alpine high temperatures around -7.

Avalanche Summary

A MIN report from Ashman (west of Smithers) describes two avalanches in north-facing gullies at lower treeline elevations see here. We have very limited reports from this region so it is import to supplement this forecast with your own observations. If you have been out, please submit any observations to the Mountain Information Network (MIN).

Snowpack Summary

An initial 10-20 cm of new snow has dusted the region, the first accumulations brought by a series of storms impacting us this week. The combination of new snow and forecast strong south winds will form thicker wind deposits at higher elevations. The new snow will likely bond poorly to the weak surface hoar and facets that have been sitting on the surface for the past week (see this MIN report).A hard crust has been reported 10-20 cm below the previous snow surface, and in some locations there is an early season crust with facets near the bottom of the snowpack.Expect an average snow depth of 60-120 cm in the alpine. This decreases dramatically at lower elevations, where the primary hazards remain the rocks, stumps, and open creeks lurking beneath thin snow cover.

Problems

Storm Slabs

An icon showing Storm Slabs
Continuing snowfall paired with strong southwest winds will keep building storm slabs on Thursday. The new snow is expected to bond poorly to the old snow surface being buried. Watch for deeper, touchier new slabs in the southwest of the region.
Be alert to conditions that change with elevation, aspect, and exposure to wind.Approach steep lee and cross-loaded slopes with caution.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Dec 13th, 2018 2:00PM

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