Avalanche Forecast

Issued: Dec 24th, 2014 7:47AM

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

Avalanche Canada rbuhler, Avalanche Canada

A buried weak layer means tricky conditions will persist for several days. Make conservative terrain choices and have a safe holiday period.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

A ridge of high pressure should keep the region dry for Thursday and Friday. On Thursday, expect mostly sunny conditions with freezing levels around 700m and light NW winds in the alpine. Friday is expected to start out sunny with increasing cloudiness during the day. Freezing levels should be around 500m and alpine winds should remain light. The next weak storm system is currently expected to arrive Friday night and persist through the weekend. Saturday may see 4-8mm of precipitation with freezing levels staying relatively low.

Avalanche Summary

On Tuesday, several natural size 1 wind slabs were reported. On Monday, reported avalanche activity was limited to one natural cornice release that did not trigger a slab as well as loose sluffing from steep terrain. On Sunday, explosive control produced storm slabs size 1-2. Going forward, natural activity is not expected but skier triggered slabs may persist for several days.

Snowpack Summary

A 40-60 cm storm slab sits above the mid-December surface hoar layer. We don't know a whole lot about the reactivity of the layer yet but appears to be most reactive at treeline in the north of the region. It may be less reactive in the Whistler area. Winds prior to burial likely destroyed the surface hoar in the alpine throughout most of the region. Strong SW winds during the storms created wind slabs which may still be a concern.

Problems

Storm Slabs

An icon showing Storm Slabs
The storm slab sits on a touchy weak layer.  It may take longer than normal for this storm slab to stabilize so use extra caution and make conservative terrain choices.  Strong winds have created wind slabs in leeward features in the alpine.
Use conservative route selection, stick to low angled terrain with low consequence.>Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Dec 25th, 2014 2:00PM