Avalanche Forecast

Issued: Dec 23rd, 2012 8:53AM

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

pgoddard, Avalanche Canada

Sea To Sky.

Summary

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Monday: Light SE winds. Alpine temperatures around -8. No precipitation.Tuesday: Light to moderate SE winds. Alpine temperature around -7. If all you want for Christmas is some more snow, you might get a little bit, starting late in the day.Wednesday: Light S winds. Alpine temperature around -6. Light snow.

Avalanche Summary

Explosive and ski testing on Sunday produced widespread avalanching to size 1.5 in the alpine and at treeline. A natural avalanche was reported on the north face of the Lions on Saturday.

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

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.>Use ridges or ribs to avoid pockets of wind loaded snow.>Be alert for areas that have been reverse loaded by winds.>

Aspects: North, North East, East, South East, South, South West, West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Loose Dry

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.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Valid until: Dec 24th, 2012 2:00PM