Avalanche Forecast

Issued: Dec 14th, 2014 8:48AM

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

rbuhler, Avalanche Canada

Cariboos.

Stability is improving but there are still avalanche problems out there. If you see anything interesting, please submit an observation using our new website tool. For more details see: http://goo.gl/Tj0xPC

Summary

Confidence

Poor - Due to the number and quality of field observations

Weather Forecast

High pressure persists for the forecast period. Monday should be mainly sunny with treeline temperatures around -10C and light to moderate southerly winds in the alpine. On Tuesday and Wednesday, conditions are much the same with a mix of sun and cloud and treeline temperatures around -10C. Alpine winds are expected to be moderate on Tuesday morning and gradually ease during the day. On Wednesday, alpine winds should be light SW.

Avalanche Summary

Two size 2 remotely triggered persistent slab avalanches were reported on Saturday. 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. On Thursday, widespread natural avalanche activity with slides up to size 4 were reported.

Snowpack Summary

A surface crust is expected up to around treeline elevation. At or above treeline, dense storm snow is sitting on a sun crust or surface hoar. In exposed alpine areas this new snow has been blasted around by strong southerly winds and has likely created deep and dense wind slabs in lee features. Reports from the region suggest that anywhere from 50-150 cm of settling snow overlies one or more weak layers which formed during November. Snowpack tests suggest that these weak layers are getting harder to trigger but still have the potential to produce large avalanches if triggered.

Problems

Wind Slabs

Strong southerly winds last week created wind slabs in the alpine and possibly at treeline. Watch for wind loaded or cross loaded slopes well below ridge crests.

Use caution in lee areas in the alpine and at treeline. Recent wind loading have created wind slabs.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Persistent Slabs

The likelihood of triggering a persistent slab has decreased with dropping temperatures but be wary of any slope that did not release during the storms or has been reloaded. Remote triggering of this layer is also 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

Valid until: Dec 15th, 2014 2:00PM