Avalanche Forecast

Issued: Jan 23rd, 2012 9:41AM

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

Avalanche Canada triley, Avalanche Canada

Summary

Confidence

Fair - Timing of incoming weather is uncertain on Tuesday

Weather Forecast

Very strong southwest winds are forecast to build overnight Monday. Heavy snowfall is expected to begin mid-morning on Tuesday. Westerly upslope areas should get 20-30 cm during the day on Tuesday and the freezing level should rise to about 900 metres. Snow is expected to continue overnight into Wednesday morning and then become flurries as winds moderate in the afternoon. Some lingering flurries should continue on Thursday as a ridge of high pressure moves into the region.

Avalanche Summary

Some whumpfing reported from ridgetops and southerly aspects that have been wind pressed. Some naturals up to size 2.5 on north and east aspects in the alpine.

Snowpack Summary

The new storm has developed a thick blanket of dry light snow above the cold dry surface. If this new storm warms up a bit, expect a storm slab to consolidate above this cold relatively weak layer. Watch for new windslabs developing due to forecast strong southwest winds. Some surface facetting during the recent cold spell. Strong temperature gradient in the top 30 cm. Stiff windslabs have developed in the alpine and at treeline. Some areas reporting a crust that is now buried by about 50 cm of cold dry light snow. Strong well settled mid-pack. Cornice structures are weak and have been growing fast, and falling off!

Problems

Wind Slabs

An icon showing Wind Slabs
The new snow is expected to be transported into new windslabs. The snow pack may develop a stiffer layer above lighter drier snow as the temperature increases during the storm.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

2 - 6

Storm Slabs

An icon showing Storm Slabs
The snow pack may develop a stiffer layer above lighter drier snow as the temperature increases during the storm. If this slab develops, we expect that it will be easily triggered and may run fast and far.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 6

Valid until: Jan 24th, 2012 8:00AM