Avalanche Forecast

Issued: Feb 2nd, 2012 8:55AM

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

ccampbell, Avalanche Canada

Cariboos.

Summary

Confidence

Good - -1

Weather Forecast

Although some clouds are expected to move into the region from time to time, generally dry conditions are expected throughout the forecast period. Freezing levels are expected to rise to 1200-1500m by midday except for above freezing alpine temperatures on Friday. Mountain top winds should remain light.

Avalanche Summary

Large looming cornices are likely to start falling off with warm temperatures and solar radiation. Large slab avalanches that propagate across entire slopes are possible, especially with heavy triggers such as step-down avalanches, cliff-drops, and cornice drops.

Snowpack Summary

Total snowpack depths are well above average or even new record depths for this time of year. Weaknesses within the upper snowpack and the facets and surface hoar buried mid-January, create the potential for large step-down avalanches, but things seem to be settling rapidly. 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.

Problems

Cornices

Large cornices are looming over many slopes. Warm temperatures and solar radiation will likely weaken them, and 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 ridgecrests, behind terrain features and in cross-loaded gullies. They can fail as very large, destructive avalanches.

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 and are expected to remain sensitive to triggers for the forecast period.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Feb 3rd, 2012 3:00AM