Avalanche Forecast

Issued: Dec 22nd, 2012 9:35AM

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: Light to locally moderate snowfall on Saturday night should ease to light snowfall by Sunday / Moderate southeast winds / Freezing level at 900mMonday: Mostly clear skies / Light southeast winds / Freezing level at 900mTuesday: moderate snowfall / Light southeast winds / Freezing level at 600mConfidence: Good for the overall pattern / Poor for specific snowfall amounts on Saturday night/ Sunday morning

Avalanche Summary

Explosives control on Friday produced storm/windslab avalanches to size 2. I would suspect ongoing new snow avalanche activity on Sunday if snowfall/winds are moderate or higher.

Snowpack Summary

The region has received an impressive amount of new snow in recent days with over a metre falling throughout the week in some areas. The snowfall was accompanied by consistently strong to extreme winds that have since backed off leaving windslabs at higher elevations and deep loose snow below treeline.A couple of layers of surface hoar were buried last week in some areas. Another deeper layer of surface hoar from late November is now well over a metre down. No activity has been reported on any of these surface hoar layers. In general, the mid-pack is reported to be well settled and strong. The early November crust/facet combination near the base of the snowpack seems to be dormant; however, the consequences of a deep release would be very serious. Avalanches at this interface would most likely require a large trigger along a thin, unsupported snowpack 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 wind-affected, upper elevation terrain. In sheltered areas, watch for sluffing in steep terrain.
Be alert to conditions that change with elevation.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

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