Avalanche Forecast

Issued: Nov 29th, 2012 9:47AM

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

jlammers, Avalanche Canada

Cariboos.

Summary

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Friday: Light to moderate snowfall / Moderate southwest winds / Freezing level at 1400mSaturday: Moderate to locally heavy snowfall / Moderate southwest winds / Freezing level at 1300mSunday: Light snowfall / Light southerly winds / Freezing level at 1100m

Avalanche Summary

No recent avalanches have been reported from the region. We welcome all observations at forecaster@avalanche.ca.

Snowpack Summary

Based on limited data streams, it appears as though the region received up to 15cm of new snow on Wednesday night. Relevant wind information has also been extremely limited; however, some data points suggest that winds were in the moderate (enough to transport snow) range. Forecast snow and increased wind values will add some more punch to this newly developing storm slab. This new slab sits over a variety of old surfaces which most likely include well settled storm snow from last week and surface hoar.There may be a thin buried surface hoar layer down about 95 cm. As well, the November rain crust now exists over 110cm down in some locations and may exist in combination with facets. These layers seems to have been unreactive in recent days, but may have the potential to 'wake-up' with additional loading.Average snow depths at treeline seem to be between 125cm and 150cm.

Problems

Storm Slabs

New snow and wind forecast for the next few days will add to a developing wind/storm slab problem. The sensitivity of this layer may be higher in some areas due to the possibility of underlying surface hoar.

If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious. This includes open crevasses on glaciers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

Although the likelihood of a release is low, the consequences of a persistent slab release could be significant. These layers may wake-up with additional loading.

Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Nov 30th, 2012 2:00PM