Archived

Avalanche Forecast

Jan 7th, 2012–Jan 8th, 2012

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

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

1: Low

The avalanche danger rating below treeline will be low

Regions: South Coast.

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

Sunday: Snowfall become heavy in the afternoon, Forecast amounts to 20cm / Strong southwest winds / Freezing levels rising to 1800m Monday: Continued moderate to heavy snowfall tapering off in the afternoon / Moderate to strong southwest winds / Freezing levels dropping from 1400m to 700m as snowfall tapers off Tuesday: Clear skies with no precipitation / Winds switching to light and northerly / Freezing level dropping to surface

Avalanche Summary

No new avalanche activity reported.

Snowpack Summary

Weaknesses within and under the 70-100+cm of storm snow will need some time to settle and fully 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.Expect further wind slab and storm slab development with forecast weather

Avalanche Problems

Wind Slabs

With forecast weather, expect stiff windslabs to develop on lee and cross-loaded terrain at treeline and in the alpine

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

Elevations: Alpine, Treeline.

Likelihood: Very Likely

Expected Size: 1 - 5

Storm Slabs

Forecast snowfall will add to the current storm slab instability.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely

Expected Size: 1 - 5

Persistent Slabs

Primarily a concern in the northern part of the region. Triggering is more likely from thin slab areas (ie: moraines or cross-loaded terrain), or from storm or wind slab avalanches stepping down to deeper weaknesses.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 6