Avalanche Forecast

Issued: Jan 8th, 2015 7:45AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Persistent Slabs and Loose Wet.

Avalanche Canada rbuhler, Avalanche Canada

The surface crust has improved stability but poor ski conditions are being reported.  Use extra caution anywhere that you are breaking through the crust.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

The warm air should break down on Friday.  Freezing levels will progressively fall to around 1000m by Friday night.  A mix of sun and cloud is expected during the day and alpine winds are expected to be moderate from the SW.  On Saturday, a weak trough crosses the south coast.  Mostly cloudy conditions, light flurries, and light alpine winds are expected. Freezing levels should be around 1000m.  Sunday should see a mix of sun and cloud, light alpine wind, and freezing levels around 1000m.

Avalanche Summary

No new slab avalanches were observed on Wednesday but a couple size 1 loose wet sluffs were ski cut. Reports from Tuesday of natural and explosive triggered slab avalanches up to size 2.5 on leeward slopes. Loose activity was also reported on steep solar aspects. Natural avalanches are not expected on Friday. Ski triggering is unlikely in areas that are capped with a supportive surface crust but caution is required anywhere the crust remains breakable.

Snowpack Summary

A thick supportive surface crust is capping the snowpack.  Below the crust is the recent storm snow which is around 50-70cm deep and sits on a previously variable snow surface that included wind affected surfaces, a freezing rain crust or sun crust, and/or surface hoar or sugary facets in sheltered terrain. In the middle of the snowpack we might find the mid-December surface hoar or crust/facet weak layers. These are now typically buried 1m or more. The old surface hoar layer may be found in sheltered shady areas at and below treeline, while the slightly deeper crust/facet layer is expected to be more widespread but also more variable.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Two persistent layers in the snowpack remain a concern. These are down around 60cm and 120cm. Triggering these layers is unlikely where the surface crust is supportive but use caution anywhere you are breaking through the crust.
Be aware of thin areas where human-triggering may be possible and may propagate to deeper instabilities.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Loose Wet

An icon showing Loose Wet
If the snow surface is moist or wet, sluffing is possible from steep terrain features. Use extra caution on or below sunny slopes. A wet sluff has the potential to trigger a larger slab avalanche.
Be cautious of sluffing in steep terrain.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 9th, 2015 2:00PM