Archived

Avalanche Forecast

Jan 6th, 2012–Jan 7th, 2012

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

4: High

The avalanche danger rating in the alpine will be high

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

Alpine

4: High

The avalanche danger rating in the alpine will be high

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: South Coast.

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Saturday: 6-8cm of snow arriving late in the day / moderate to strong southwest winds / freezing level at 1600m Sunday: 15-20cm of snow / strong southwest winds / freezing level climbing from 1600 to 2000m throughout the dayMonday: 15-20cm of snow / moderate southwest winds / freezing level lowering to 1000m throughout the day

Avalanche Summary

Widespread natural avalanche activity up to Size 3 was reported throughout the week. Fresh storm and wind slabs, as well as deeply buried persistent slabs remain sensitive to human triggers.

Snowpack Summary

Weaknesses within and under the 70-100+cm of storm snow will need some time to settle and strengthen. Persistent weaknesses remain a concern in the northern part of the region. Buried surface hoar on sheltered treeline slopes and below and facets with associated crusts in exposed treeline and alpine areas are probably down well over a metre in most places, and facets lurk near the base of the snowpack in shallow rocky areas. Wind-loading has resulted in highly variable slab thicknesses with the potential for fractures triggered in highly sensitive thin slab areas to propagate into highly destructive deep slab avalanches. Furthermore, weaknesses within the slab create the potential for step-down fractures.

Avalanche Problems

Wind Slabs

Watch for sensitive wind slabs lurking below ridgecrests, behind terrain features and in cross-loaded gullies.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 4

Storm Slabs

Watch for touchy storm slabs on steep unsupported terrain features.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 5

Persistent Slabs

Primarily a concern in the northern part of the region. Especially easy to trigger from thin slab areas, or from storm or wind slab avalanches stepping down to deeper weaknesses.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 6