Avalanche Forecast

Issued: Dec 16th, 2014 7:37AM

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

rbuhler, Avalanche Canada

Cariboos.

A deeply buried weak layer remains a concern, especially on steep north facing slopes in the alpine. Remote triggering of this layer may still be possible.

Summary

Confidence

Fair - Due to the number and quality of field observations

Weather Forecast

The high pressure will continue to dominate for Wednesday and Thursday. On both Wednesday and Thursday, expect a mix of sun and cloud and treeline temperatures around -10C. On Friday, the high pressure begins to break down as a weak system pushes into the interior from the coast. Currently the models are not showing any substantial precipitation but it is a possibility. Alpine winds are expected to remain light from the SW for the forecast period expect possibly on Thursday night when they may increase to moderate.

Avalanche Summary

No new avalanches were reported on Monday or by publish time on Tuesday. 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. A new layer of surface hoar is currently forming on the snow surface. 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. We received reports that this deep weak layer has resulted in remotely triggered avalanches over the weekend.

Problems

Deep Persistent Slabs

The likelihood of triggering a deep persistent slab has decreased but the consequences remain very high. Be wary of any slopes that did not release during the storms. Heavy triggers such cornice falls may be able to trigger a deep weak layer.

Avoid common trigger zones including thin snowpack areas, near rocky outcrops, and steep alpine slopes.>Remote triggering is a concern, watch out for adjacent slopes.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Dec 17th, 2014 2:00PM