Avalanche Forecast

Issued: Dec 18th, 2012 9:17AM

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

Avalanche Canada ccampbell, Avalanche Canada

Summary

Confidence

Fair - Due to limited field observations for the entire period

Weather Forecast

Wednesday: Light snowfall with around 5cm of accumulation, strong southwesterly mountaintop winds increasing to extreme overnight, and freezing levels remaining at or near valley bottoms. Thursday: Moderate snow with 5-10cm of accumulation, moderate southerly winds and freezing levels in valley bottoms. Friday: Light flurries tapering off and clearing throughout the day, light southwesterly winds, and freezing levels remaining in valley bottoms.

Avalanche Summary

Small loose snow avalanches have been from steep terrain in the recent low density storm snow. Due to our limited observations for this region at this time, your avalanche observations are welcome at forecaster@avalanche.ca

Snowpack Summary

The upper snowpack comprises deep amounts of unconsolidated snow in sheltered locations, and soft slabs in open, exposed locations. These slabs are most likely immediately behind ridge crests and downslope ribs. There's ample recent snow available to fuel slab development if winds pick up. Overall, the top and mid-snowpack is reported to be settling well. Persistent and Deep persistent instabilities (surface hoar and an early November crust, respectively) located in the middle and near the bottom of the snowpack may still be a concern but there's little recent evidence of them. It is important to know that we have very limited observations for this region. Digging down and making your own observations, especially in thinner snowpack areas, remains a good idea to assist safe slope selection. You're looking for weak layers that pop or drop in stability tests.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs are able to set up readily at this time due to the amount of low density new snow available for wind transport. Buried wind slabs are reported to exist below some of the new snow in exposed locations, especially on N and E aspects.
Be cautious as you transition into wind affected terrain.>Avoid freshly wind loaded features.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Dec 19th, 2012 2:00PM