Avalanche Forecast

Issued: Jan 21st, 2012 9:25AM

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

Avalanche Canada jfloyer, Avalanche Canada

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Sunday: A band of snow arrives late in the afternoon, bringing 10-15 cm to this region. Freezing levels should stay at valley bottom and winds will be strong southerly. On Monday, unstable air will bring another 10-15 cm new snow. On Tuesday, another intense Pacific frontal system arrives, which will likely bring 20-30 cm new snow to this region, with freezing levels rising to around 1200 m. Continued strong westerly/southwesterly winds.

Avalanche Summary

An avalanche cycle up to size 2.5 was reported on Saturday. Both slab and loose snow activity was noted at all elevations.

Snowpack Summary

Dense new snow is setting up a fresh storm slab on top of the previous cold, low density snow from the last few days. An interface down 30-50 cm just above a rain crust is producing easy but resistant shears in snowpack tests. The rain crust itself lies buried around 40-60cm below the surface up to around 1900 m. The bond at this crust is reported to be quite good. On steep slopes, this interface, or the one above it, definitely has the potential to act as a good sliding surface. Weak layers lower in the snowpack have generally ceased to be of concern, except perhaps in very isolated, thin rocky areas.

Problems

Storm Slabs

An icon showing Storm Slabs
Heavy amounts of dense new snow has fallen on existing low density snow. This has set up unstable conditions in the upper snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Wind Slabs

An icon showing Wind Slabs
New snow and strong winds have set up touchy new wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Valid until: Jan 22nd, 2012 8:00AM