Avalanche Canada pgoddard, Avalanche Canada

Sea to Sky Avalanche Forecast

Dec 24th, 2012 8:15AM

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

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain on Tuesday

Weather Forecast

Tuesday: Moderate to strong SE winds. Alpine temp -8. Light snow.Wednesday: Light SW winds. Alpine temp -8. A few cm snow.Thursday: Light SW winds. Alpine temp -7. No precipitation.

Avalanche Summary

On Sunday, several size 1-1.5 wind slabs were triggered by explosives and skiers. One size 2 slab was triggered in a steep high alpine start zone.

Snowpack Summary

Over a metre of snow has fallen this week with strong SE winds, which has created wind slabs in alpine and open treeline terrain. New cornices exist. In sheltered areas below treeline, very deep loose snow has built up. Three surface hoar layers in the upper/mid snowpack appear to be gaining strength. In general, the mid-pack is strong.Near the base of the snowpack, a crust/facet layer has become unlikely to be triggered. However, professionals are still mindful of thin snowpack trigger areas or large loads which could wake it up again, leading to a very large avalanche.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Likely - Possible

Expected Size

1 - 4
Winds have shifted available snow into slabs behind ridges and ribs. These could be triggered by the weight of a person or snowmobile.
Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Stay well to the windward side of corniced ridges.>Use ridges or ribs to avoid pockets of wind loaded snow.>

Aspects:

North, North East, East, South East, South, South West, West.

Elevations:

Alpine, Treeline.

Loose Dry

An icon showing Loose Dry

Likelihood

Likely

Expected Size

1 - 4
The volume of loose dry snow could knock you over or carry you into a terrain trap. Be cautious in any steep terrain.
On steep slopes, pull over periodically or cut into a new line to manage sluffing.>Be aware of party members below you that may be exposed to your sluffs.>

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Valid until: Dec 25th, 2012 2:00PM