Archived

Avalanche Forecast

Jan 4th, 2014–Jan 5th, 2014

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

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

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

Regions: South Coast.

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

Sunday: Mix of sun and cloud with an area of warm air moving into alpine elevations. Above freezing temperatures are expected in the Alpine.Monday: Continued warm air at higher elevations with light to moderate Southwest winds and no precipitation.Tuesday: Cloudy with light to moderate Southwest winds and seasonal temperatures in the alpine.

Avalanche Summary

Natural loose snow and storm snow avalanches size 1.0-1.5 were reported from steep South aspects in the alpine and at treeline in the Duffey Lake area. Natural avalanches size 1.0-1.5 from steep wind loaded pockets at ridgeline were reported from the Coquihalla, as well as several size 2.0-2.5 storm slab avalanches from the steep North aspect of Mount Cheam.

Snowpack Summary

New snow is expected to be poorly bonded, especially on wind-loaded slopes. Snowpack depths vary greatly across the region with 180cm at treeline in the Cascades but only about 80cm in the Duffey Lake area, and terrain below treeline is still mostly below threshold for avalanche activity. In general the snowpack is shallow with a faceted and weak lower half, but also highly variable. Snowpack testing on a NW facing slope at 2150m in the Duffey Lake area on Thursday produced easy sudden planar compression test results, and a RB2, whole block release Rutschblock result down 27cm on the late-December surface hoar, this layer now has an additional 15-25 cms since the Thursday evening storm. Early season riding hazards such as rocks, stumps and logs are lurking below the surface at treeline elevations and below.

Avalanche Problems

Wind Slabs

Recent storm snow and strong winds have created pockets of wind slab in the alpine and at treeline. Wind slabs may be sitting above weak shallow snowpacks.

Use ridges or ribs to avoid pockets of wind loaded snow.>Be careful with wind loaded pockets near ridge crests and in terrain depressions>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Persistent Slabs

Weak layers of buried surface hoar, crusts, and depth hoar may continue to be triggered by light additional loads like skiers and riders. Wind slabs above these weak layers may step down resulting in larger and more dangerous avalanches.

Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.>Use caution in shallow snowpack areas where triggering is more likely.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 4