Avalanche Forecast

Issued: Dec 5th, 2018 4:35PM

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

Avalanche Canada kdevine, Avalanche Canada

The snowpack is gaining strength, but keep the persistent slab in mind when choosing objectives. Make quality snowpack observations before pushing into more committing terrain.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

WEDNESDAY NIGHT - Cloudy with clear periods / light southeast winds / alpine low temperature near -12THURSDAY - A mix of sun and cloud / light southerly winds / alpine high temperature near -7FRIDAY - Sunny with cloudy periods / light south wind / alpine temperature steady near -7SATURDAY - Cloudy with sunny periods / light southerly winds / alpine high temperature near -6, low temperature near -8

Avalanche Summary

No new avalanches have been reported.Several large, notable avalanches that were reported in the region between November 24 and December 1 are listed below:On December 1 a natural size 3 slab avalanche was seen on Mt. Begbie (east to northeast aspect above 2000 m). It is likely that this avalanche was initiated by a large trigger such as a rock or cornice fall, and that it ran on the October crust.On November 29 an explosives triggered size 2.5 avalanche ran on the October crust on a north to northeast aspect at 2300 m.On November 24 a human triggered size 3 avalanche was reported in the region. This avalanche likely ran on the October crust, as it was reported as a full depth avalanche. Two reports on this avalanche can be found on the Mountain Information Network. MIN

Snowpack Summary

35-65 cm of snow sits on a layer of surface hoar (weak feathery crystals) and sun crust on steeper south facing slopes. The surface hoar is mostly found at treeline, but it may be found in sheltered alpine areas. While this layer is becoming more difficult to trigger, recent snowpack tests still suggest that it is worth keeping in mind for now, especially in wind loaded areas.At the base of the snowpack is a crust that formed near the end of October. This crust is associated with weak, faceted (sugary) snow and is most prominent in the alpine. Concern for this layer is dwindling but it is still worth considering in places such as steep, rocky, alpine terrain, especially where the snowpack is shallow. It would likely take a large trigger such as a cornice fall to produce an avalanche on this layer.Snowpack depths taper quickly with elevation, many areas have over 200 cm in the alpine, between 100-170 cm at treeline, and 10-100 cm below treeline.

Problems

Persistent Slabs

An icon showing Persistent Slabs
35-65 cm of snow sits on a layer of surface hoar (weak feathery crystals) and sun crust on steeper south facing slopes. It is likely that this layer will be most reactive in areas where wind loading has promoted slab development.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Watch for signs of instability such as whumpfing, cracking, or recent avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 6th, 2018 2:00PM