Avalanche Forecast

Issued: Nov 25th, 2016 3:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

Heads up! Heavy snowfall is forecasted for the region on Saturday and will increase avalanche danger over the weekend.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

After a break in the weather on Friday, the South Columbia will see another storm front moving in early Saturday morning and stalling over the region until late in the evening. We can expect to receive heavier snowfall from this system, with accumulations of up to 25cm under light wind and a freezing level rising from 500 to 1000m. Flurries may produce trace snowfall amounts on Sunday before we see a clearing in the weather on Monday.

Avalanche Summary

Although no natural avalanches have been reported in the region, a ski cut into wind slab on a north-facing treeline feature produced a 10-15cm thick size 1 avalanche on Thursday. Isolated unsupported pockets of wind slab have been reactive to skier traffic at higher elevations and new snow is expected to increase the size, distribution, and reactivity of slabs.

Snowpack Summary

Recent snowfall has undergone significant redistribution in higher elevation and exposed areas. The strong southerly winds we experienced Thursday night only began to ease midday on Friday. Storm slabs and wind slabs have been building and consolidating under the influence of the wind. 50-80cm of snow now covers the widespread Nov 13 crust. Several interface layers exist within the snow above the crust, most notably a sun/temperature crust which formed on steep solar aspects on November 22. Below the November 13 crust the mid and lower snowpack are well consolidated, with moist snow present at treeline and below.

Problems

Storm Slabs

An icon showing Storm Slabs
Recent snowfall has undergone heavy wind effect. Forecast snowfall will increase danger from storm slabs, especially in exposed lee terrain. The potential exists for increased load from new snow to trigger deep instabilities.
Use caution in lee areas in the alpine and treeline. Storm snow is forming touchy slabs.Use ridges or ribs to avoid pockets of wind loaded snow.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Valid until: Nov 26th, 2016 2:00PM