Avalanche Forecast

Issued: Jan 7th, 2014 8:13AM

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

Avalanche Canada mbender, Avalanche Canada

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Wednesday: A Pacific frontal system starts to affect the interior regions. Cloudy with light to locally moderate snowfall, moderate to strong west winds. Freezing level in the valley bottom.Thursday: Moderate snowfall in the western portions of the region, light snowfall in the eastern portions, alpine temperatures -7, moderate west winds.Friday: Light snowfall, alpine temperatures -5, freezing level 1200m, winds moderate west and southwest

Avalanche Summary

Recent reports from the last 3 days indicate that the natural avalanche activity seems to be isolated to a windslab and cornice releases up to size 2.5. These are running within the storm snow in the alpine and at treeline elevations. There was also a report of a glide crack release running naturally to size 3.

Snowpack Summary

Up to 50cm of recent new snow lies on top of old wind slabs, a thin melt freeze crust below 2100m and numerous weak layers. Down 40 -100cm is the mid December layer comprised of surface hoar, stellars and/or a crust. Around 70 -140cm down is the early December surface hoar, faceted snow and/or crust.There are two deeper layers of note. The late-November persistent weak layer consists of a sun crust on steep south facing slopes and surface hoar in sheltered areas and is now buried 90-160cm below the surface. The October deep persistent weak layer consists of a layer of facets sitting on a crust at the base of the snowpack. This layer is predominantly found on northerly aspects at treeline and in the alpine. The depth of both these layers makes directly triggering an avalanche on them unlikely (maybe a heavy load on a thin spot in steep terrain). Their presence could, however, increase the size of a potential avalanche through step-down.

Problems

Wind Slabs

An icon showing Wind Slabs
Recent new snow and moderate winds have created windslabs on a variety of aspects.
Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
The presence of persistent weak layers increases the likelihood of larger avalanches that could release to a depth of a meter or even more.
Avoid convexities or areas with a thin or variable snowpack.>Be aware of thin areas that may propogate to deeper instabilites.>Dig down to find and test weak layers before committing to a line.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Jan 8th, 2014 2:00PM