Avalanche Forecast

Issued: Nov 24th, 2015 8:43AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wind Slabs.

Avalanche Canada swerner, Avalanche Canada

The snowpack is extremely variable depending on aspect and elevation. Stiff wind slabs with wide propagations may be ripe for rider triggering. Check out the Mountain Information Network. Give info, get info!

Summary

Weather Forecast

The arctic high remains stationary over the north giving cool and dry conditions on Wednesday. Treeline temperatures will hover near -9 with light winds from the northerly quadrants. Late Wednesday, warm air aloft will start to invade the coastal regions allowing temperatures to rise anywhere from 0-5 degrees between 1100-2500 m. Ridgetop winds will also change, blowing light from the southwest well into the weekend.

Avalanche Summary

On Monday north of Terrace, a natural slab avalanche cycle was reported on N-NE aspects up to size 2.5 with a smaller size 1 observed. The newly formed slab at higher elevations may remain ripe for human triggering for the next few days, especially in areas where persistent weak layers exist.

Snowpack Summary

The snowpack is extremely variable depending on aspect and elevation, with new wind slabs developing on some reverse loaded southerly slopes and widespread surface crusts at lower elevations. At upper elevations, last weekends storm produced stiff wind slabs on northerly aspects which remain reactive, especially in the northern parts of the region where storm accumulations saw up to 30 cm and ridgetop winds were in the extreme values. Due to limited observations, I have very little confidence in what that underlying structure may be, although I suspect faceting, crusts and surface hoar may exist. However; how are they adjusting and reacting as shears? Are they visually distinct and reacting like a cash register when tested? Or are they becoming hard to find with a more resistant shear characteristic? If I were traveling in the mountains, I'd maintain an investigative approach and dig down to test for weak layers before committing to a slope.

Problems

Wind Slabs

An icon showing Wind Slabs
Watch for new wind slabs on opposite slopes due to changing winds from the north. Destructive wind slabs from last weekends storm may still exist, watch for wide propagations, especially in the lee of ridgecrests.
Be alert to conditions that change with elevation and use a cautious approach to terrain while gathering information along the way.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>Be careful with wind loaded pockets. Be aware of wide variation in snowpack depth>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Nov 25th, 2015 2:00PM