Archived

Avalanche Forecast

Dec 1st, 2016–Dec 2nd, 2016

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Glacier.

Continue to be cautious on large slopes in the alpine, and avoid likely triggering spots like convex rolls and thin snowpack areas. Expect avalanche danger to increase over the next few days; a storm may overload a persistent weak layer down 1 meter.

Weather Forecast

Today is looking mostly cloudy with flurries. It's possible there may be a few sunny breaks in the alpine, with temps of -9'C with light W'ly winds. A storm is expected to hit mid-day on Friday, bringing ~10-15cm of snow with moderate SW winds loading lees. Saturday the storm continues with another ~15cm of snow and moderate to strong winds.

Snowpack Summary

10-20cm of powder overlies settled snow & windslabs in the alpine. The Nov 13 crust is buried ~60 and 100cm deep. In most areas the crust seems to be bonding well but is of most concern on S'ly aspects. Tests on a SW aspect, 2075m indicated that the crust may be triggered by light loads and that it is capable of propagating into a large avalanche.

Avalanche Summary

Natural avalanche activity has been limited to small loose avalanches over the past few days. A field team yesterday ski cut numerous steep unsupported rolls while descending from Lookout Col and found the snow to be unreactive in that area.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Avalanche Problems

Wind Slabs

At ridgecrests and on lee features, pockets of windslab are hidden by 10-20cm of powder. These wind slabs may be triggered by skiers and snowboarders.

Use caution in lee areas. Recent wind loading have created wind slabs.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Persistent Slabs

A crust buried up to 1m deep may become increasingly reactive over the weekend and be hard to predict. Test results show variability: in some areas it is unreactive and in others it may be triggered by light loads (you!) and produce large avalanches.

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes. Choose regroup spots carefully.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 3