Avalanche Forecast

Issued: Jan 21st, 2012 9:52AM

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

Avalanche Canada triley, Avalanche Canada

Summary

Confidence

Good - -1

Weather Forecast

The current storm is expected to continue bring snow overnight Saturday into Sunday morning, resulting in another 10-15 cm for the Cariboo and 15-20 cm for the Monashee and Selkirk. Westerly upslope areas may see a bit more, maybe an added 5-10 cm. The wind should drop down to about 20 km/hr in the alpine overnight and then become gusty from the west as a weak ridge of high pressure moves across the interior during the day on Sunday. The next pulse is expected to arrive from the coast early Monday morning, bringing snow to the interior ranges on Monday and overnight into Tuesday morning. Tuesday and Wednesday look to be warmer and quite wet; stay tuned we should know more on timing and intensity tomorrow.

Avalanche Summary

I suspect that there has been widespread sluffing in steep terrain, and natural activity from wind loaded slabs in the alpine and at treeline. There have been a couple of natural cornice falls and natural ice falls releasing slabs up to size 3.0. Cornices and Ice falling onto slopes below is a very large trigger. The interesting comment from this region is, that some of these very large triggers did not release slabs on the slopes below. Fast moving sluffs have also been reported from this region.

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 22nd, 2012 8:00AM