Archived

Avalanche Forecast

Nov 24th, 2011–Nov 25th, 2011

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

3: Considerable

The avalanche danger rating below treeline will be considerable

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

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.

Avalanche Problems

Storm Slabs

A warm pineapple system dominated the weather yesterday, bringing heavy snowfalls in the alpine, and heavy rain below 1200m. Large avalanches occurred in the highway corridor, including one size 4, three size 3.5's, and several size 2-3.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Persistent Slabs

A surface hoar layer is buried up to 130 cm deep. It has become less sensitive to skier triggering but remains a concern. Snowpack tests give sudden planar results. Avalanches triggered in upper layers may step down to this persistent layer.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely - Possible

Expected Size: 1 - 3

Wind Slabs

Wind slabs formed on Nov. 22-23 are now buried down 40cm, and are reactive in field tests (resistant planar).

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2