Avalanche Forecast

Issued: Dec 23rd, 2013 8:53AM

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

Avalanche Canada swerner, Avalanche Canada

Summary

Confidence

Fair - Timing of incoming weather systems is uncertain

Weather Forecast

A ridge of high pressure will set up over the Interior regions bringing a dry, cool northwest flow Tuesday-Wednesday. The next system should arrive Wednesday night bringing snow, wind and warming. Generally, the pattern is repeating itself. Tuesday: Cloudy. Alpine temperatures -8. Ridgetop winds moderate gusting strong from the West.Wednesday: Snow amounts up to 20 cm. Alpine temperatures -8. Ridgetop winds moderate-strong from the West. Thursday: Cloudy. Snow amounts 10 cm. Alpine temperatures -5. Ridgetop winds light from the South. Freezing levels rising to 1100 m.

Avalanche Summary

Numerous loose dry avalanches up to size 2 were reported through the region.

Snowpack Summary

New snow (up to 40 cm in some places) has buried older wind slabs in exposed terrain at treeline and above. The new storm snow is settling quickly, however storm slabs have been touchy especially in wind affected areas. The average snowpack depths at treeline range from 100 cm -150 cm.Buried down 60 cm is a surface hoar, and facet layer. This layer has recently been reactive to riders and natural triggers and both cracking and whumpfing have been noted.Digging deeper down 70-90 cm is the late-November interface, which consists of a sun crust/ facet combo on steep south facing slopes and larger, proud surface hoar crystals in sheltered areas at lower elevations. This layer is generally considered to be "stubborn" to trigger. However, professionals are keeping a close eye on this layer. At the base of the snowpack the October crust is most predominant on north-facing alpine slopes with smooth ground cover. Triggering this weakness is unlikely, but if triggered the resulting avalanche would be very large and consequential.

Problems

Storm Slabs

An icon showing Storm Slabs
New storm snow may be touchy and reactive, especially in wind affected areas. Natural avalanche activity is expected. Further loading and smaller avalanches may trigger buried weak layers and initiate large- very large avalanches.
Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.>The new snow will require several days to settle and stabilize.>Choose conservative lines and stick to supportive, low angle terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
Persistent weak layers of facets, surface hoar, and/or a crust exist in the upper 90 cm of the snowpack. With more load they may be susceptible to triggering, creating large - very large destructive avalanches.
Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>Avoid convexities or areas with a thin or variable snowpack. Thin areas may propagate to deeper instabilities.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

3 - 5

Valid until: Dec 24th, 2013 2:00PM