Avalanche Forecast

Issued: Dec 1st, 2011 9:22AM

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

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Poor - Due to limited field observations

Weather Forecast

No snow is expected for the next three days. Strong winds are expected from the north early friday morning tapering to moderate and northerly for the rest of the day and into saturday and sunday. Freezing levels are expected to remain at or near valley bottom for all three days.

Avalanche Summary

No new reports received since the weekend; this may say more to the lack of information from the field and little about field conditions. If you have any observations from the field, please drop us an email: forecaster@avalanche.ca. Information and observations from you can really help.

Snowpack Summary

Snowfall accumulations have not been sufficient to create an avalanche problem below treeline where the snowpack sits at about 30-60cms. Regardless, slopes at higher elevations have been large enough to run down to terrain located well below treeleine. In the alpine, and at treeline the snowpack depth generally sits anywhere from 80-120cm with deposits of up to 400 cms on wind-loaded features.Although not widespread, reports suggest that strong to extreme winds in some parts of the region have stripped west aspects of snow creating wind slabs on lee and cross-loaded aspects in the alpine and at treeline. Many of these new windslabs could be sitting on the reactive October rain crust located a few centimetres above the ground. This rain crust may have weak, overlying facets and is widespread in the alpine and isolated in its distribution at treeline in some parts of the region and non-existent in others.The 'take home' message is that the region as a whole is data-sparse and extremely variable in terms of snowpack structure. When heading into avalanche terrain, do so gradually and take the time to gather terrain-specific information. Any reports from the field are highly valued. Any observations can be sent to: forecaster@avalanche.ca

Problems

Wind Slabs

An icon showing Wind Slabs
Expect touchy windslabs in lee or cross-loaded terrain at treeline and in the alpine. The nature of this problem will become more complicated with forecast northerly winds.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
Avalanche activity on this layer has decreased, but the problem has not gone away. If triggered, avalanches on this layer could be highly destructive.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 6

Valid until: Dec 2nd, 2011 8:00AM