Avalanche Forecast

Issued: Jan 15th, 2015 7:49AM

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

Avalanche Canada esharp, Avalanche Canada

Snowfall will be highly variable across the region.  Forecast danger ratings are for areas that receive greater accumulations

Summary

Confidence

Good - Forecast snowfall amounts are uncertain

Weather Forecast

Synopsis: A fast moving cold front will bring precipitation to the interior of the province through tonight and Friday with the next system forecast to arrive Saturday night.  Overnight and Friday:  5-20cm new snow with the highest amounts forecast for Kootenay Pass, winds will be moderate to strong from the southwesterly with freezing levels at 1000m.  Saturday: clearing briefly with light northwesterly winds becoming southwesterly and freezing levels at valley bottom.  Sunday: moderate to heavy snowfall  becoming rain at lower elevations with light westerly winds and freezing levels at 1500m.

Avalanche Summary

Avalanche activity has slowed in recent days, but the occasional avalanches that are being reported suggest that there is still the potential for human-triggering of large avalanches.  Recent avalanche reports have described large slides ranging from size 2.5 to 3 .  Several of these were remotely triggered by ski touring groups from distances as far as 100m away.

Snowpack Summary

The forecast snow will burry a layer of Large surface hoar crystals on the old snow surface. Underneath this a thin frozen crust can be found up to about 1900m on N aspects and to ridgeline on south aspects. Deeper in the snow pack our main concern continues to be another crust/surface hoar combo buried in mid-December. This weak layer can be found between 60-120cm down and still has the potential to be triggered by people to produce surprisingly large avalanches. Avalanche professionals in the region are  treating this interface with suspicion. Near the base of the snowpack the facet/crust layer has mostly been dormant, however, isolated recent activity in the Bonnington Range suggests it may still be reactive in isolated terrain.

Problems

Wind Slabs

An icon showing Wind Slabs
The forecast snow will fall on a layer of surface hoar above a widespread crust. In areas that receive the greater snowfall amounts this could result in touchy avalanche conditions especially in wind loaded terrain.
Enter your line well below ridge crests to avoid wind loaded pillows.>Be cautious of sluffing in steep terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Persistent Slabs

An icon showing Persistent Slabs
Wind slab avalanches may be able to trigger deeper weak layers. Persistent slabs may also be triggered by the weight of a person or snowmobile in specific areas such as thin spots or convexities in the slope.
Avoid convexities or areas with a thin or variable snowpack.>Smaller avalanches may trigger deeper instabilities.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Jan 16th, 2015 2:00PM