Avalanche Forecast

Issued: Feb 4th, 2012 9:34AM

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

pgoddard, Avalanche Canada

Cariboos.

Avalanche danger will peak during the heat of the day.

Summary

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

Expect mostly clear skies, warm alpine temperatures, light winds and no precipitation for the next few days. Alpine temperatures should become a little bit cooler by Monday.

Avalanche Summary

Numerous loose snow avalanches and a few slabs were triggered by warming and solar radiation on Friday. In some cases, icefall or cornice fall was the trigger. Further south in the Columbias, large natural avalanches released deep in the snowpack, in some cases near the ground on facets.

Snowpack Summary

Very warm alpine temperatures melted the surface layers on Friday. In areas which had an overnight freeze, a sun crust now exists to ridge top on solar aspects. In areas which are yet to re-freeze, weak slab or loose snow avalanche conditions are likely to continue.Snowpack tests on the mid-January facets down 80-150cm consistently produce sudden fractures and this weakness seems to be particularly touchy below 1500m where it is shallower and sits on a crust. Weak wind slabs and large fragile cornices are lurking in exposed lee and cross-loaded terrain.Total snowpack depths are well above average or even new record depths for this time of year.

Problems

Cornices

Large cornices are looming over many slopes. They are weakest when it's warm and sunny. A falling chunk could trigger an avalanche on the slope below.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 4

Wind Slabs

Wind slabs are generally lurking below ridge crests, behind terrain features and in cross-loaded gullies.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 6

Storm Slabs

Large storm slab avalanches have been occurring for the past week may remain sensitive to triggers until temperatures cool. In some cases these are failing on persistent weak layers buried in January.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Feb 5th, 2012 3:00AM