Avalanche Forecast

Issued: Dec 15th, 2014 8:39AM

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

rbuhler, Avalanche Canada

Cariboos.

A deeply buried weak layer is still producing large destructive avalanches in isolated areas and may be remotely triggered from a distance. Use extra caution around steep, unsupported alpine terrain.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

High pressure persists over the interior for the forecast period. On Tuesday, expect a mix of sun and cloud, treeline temperatures around -12, and light alpine winds. Conditions should be similar on Wednesday and Thursday with a mix of sun and cloud, treeline temperatures around -10, and light alpine winds.

Avalanche Summary

No new avalanches were reported at publish time on Monday. On Sunday, snowmobiles remotely triggered a persistent slab with a crown depth around 1.5m in the Allan Creek area. On Saturday, two size 2 remotely triggered persistent slab avalanches were reported. These were triggered from 250m away and released 80-100cm down on the old rain crust from early November. These occurred around 2000-2200m elevation on NW aspects.

Snowpack Summary

A surface crust exists up to around 1800m elevation. Above this elevation is dry storm snow which is settling out and faceting.Â A new layer of surface hoar is currently forming on the snow surface.Â In exposed alpine terrain, strong southerly winds last week may have resulted in variable distribution of the surface snow and the formation of wind slabs. The early November crust/facet layer is down around 1 m in the south of the region, probably less in the north.Â We received reports that this deep weak layer has resulted in remotely triggered avalanches over the weekend.Â

Problems

Persistent Slabs

The likelihood of triggering a persistent slab has decreased but the consequences remain very high. Be wary of any slopes that did not release during the storms. Remote triggering of this layer may be possible.

Avoid common trigger zones including thin snowpack areas, near rocky outcrops, and steep alpine slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Wind Slabs

Strong southerly winds last week created wind slabs in the alpine. Triggering these slabs may have become more stubborn but they remain a concern, especially in steep, unsupported terrain.

Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 16th, 2014 2:00PM