Avalanche Forecast

Issued: Dec 8th, 2012 9:10AM

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

mbender, Avalanche Canada

Cariboos.

Summary

Confidence

Poor - Due to limited field observations for the entire period

Weather Forecast

Sunday: Generally overcast with light amounts of precipitation accompanied by winds from the west 20-30km/h switching to the northwest at 30-40km/h in the afternoon.Alpine temperatures -8 degrees.Monday: A warm front is expected to give a rise in freezing levels to 800m. Light precipitation along with moderate to strong northwesterly winds. Alpine temperatures -9.Tuesday: Light to locally moderate precipitation. Alpine temperatures -8 with a freezing level at 900m. Moderate southwesterly winds.

Avalanche Summary

There are limited recent observations from this region.

Snowpack Summary

The storm snow from the past week has has settled and been redistributed by the wind. Instabilities (surface hoar layer on sheltered northerly aspects and a thin sun crust on steep southerly aspects) may exist within or down 50-70 cm. We have very limited information on the extent or sensitivity of these layers, but suspect them to be reactive under the load of the new snow. A second buried surface hoar layer, down about 115 cm, and the early November rain crust (facet-crust combo), over 140cm down in some locations, remain a concern for isolated deep slab avalanches.Average snow depths at treeline seem to be between 150 and 200cm. Elevations below 1500m are still reported as below threshold.In general, snowpack data is sparse in this region and significant variations likely exist from one drainage to another. Digging down and making your own observations will be critical to safe slope selection. Any observations from the field are greatly appreciated. Email us at forecaster@avalanche.ca.

Problems

Wind Slabs

Expect to find buried and newly formed windslabs in exposed lee slopes and cross-loaded gullies well below ridge crests.

Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 5

Deep Persistent Slabs

Although the likelihood of a release is low, the consequence of a deep persistent slab release is very high. These layers may wake-up with additional loading.

Carefully evaluate and use caution around thin snowpack areas.>Be aware of thin areas that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Dec 9th, 2012 2:00PM