Avalanche Forecast

Issued: Dec 22nd, 2012 9:39AM

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

Avalanche Canada jlammers, Avalanche Canada

Avalanche danger ratings are based on light to locally moderate accumulations on Saturday night. If snowfall amounts are higher, the danger rating will increase.

Summary

Confidence

Poor - Forecast snowfall amounts are uncertain on Sunday

Weather Forecast

Sunday: Moderate snowfall on Saturday night should ease to light snowfall by Sunday / Moderate southeast winds / Freezing level at surfaceMonday: Mostly clear skies / Light southeast winds / Freezing level at surfaceTuesday: Light to moderate snowfall / Light southeast winds / Freezing level at surfaceConfidence: Generally good for the overall pattern / Poor for specific snowfall amounts on Saturday night/ Sunday morning

Avalanche Summary

Explosives controlled avalanches to size 2 were observed in the region in the last 2 days. I'm unaware of any significant recent natural activity. All avalanche activity observed was within the recent storm snow.

Snowpack Summary

The region has seen a daily supply of moderate to locally heavy snow accumulations over the past week. In the alpine and in exposed areas at treeline, the new snow most likely exists as a windslab. The recent snow has been settling well; however, weaknesses may still exist within the storm interfaces.A layer of surface hoar buried on Dec 10 exists at treeline in the Duffey Lake area and may be more widespread. A bit deeper in the mid snowpack you might find a surface hoar layer from late November; however, tests seem to be showing limited reactivity on this layer. A generally consolidated mid-pack overlies the deeply buried November crust/facet layer which does not seem to be reactive as of late. This layer has not been observed in the Coquihalla area.

Problems

Storm Slabs

An icon showing Storm Slabs
Moderate winds and new snow are likely to promote ongoing surface instabilities. Triggering will be most likely in leeward, upper elevation terrain. Watch for sluffing in steep sheltered terrain.
Be cautious as you transition into wind affected terrain.>Be alert to conditions that change with elevation.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 23rd, 2012 2:00PM