Archived

Avalanche Forecast

Mar 10th, 2012–Mar 11th, 2012

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

2: Moderate

The avalanche danger rating at treeline will be moderate

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

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Northwest Inland.

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Sunday: light snowfall - light southerly winds - freezing level at 500m Monday: trace amounts of snow with some clearing- light southeast winds - freezing level at 400m Tuesday: very light snowfall - light southwest winds - freezing level at surface

Avalanche Summary

Observations have been limited, but reports suggest that fresh wind slabs are touchy with a few small skier-triggered 10-40cm thick slabs on wind-exposed rolls at treeline and below.

Snowpack Summary

Intense wind-loading has taken place with snow surfaces either getting scoured or packed into hard wind slabs. Warm temperatures and sun-exposure and more recent cooling have created crusts on all aspects below around 1000m and some areas as high as 1600m. The mid February interface, down around 60cm, is variable and generally consists of a strong melt freeze crust below 1000m. Above that elevation, expect to find buried facets, and/or surface hoar (in more sheltered areas), and/or a sun crust on southern aspects. The surface hoar is not widespread, but is responsible for much of the larger avalanches that occurred earlier this week. This layer should be on your radar, as it may be susceptible to rider triggers.

Avalanche Problems

Wind Slabs

Recent intense winds have deposited fresh wind slabs, generally below ridgecrests, behind terrain features and in gullies. Cornices are also large and weak, and could trigger large wind slabs below.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 5

Persistent Slabs

The persistent weak layer continues to be buried by a few cm each day. Avalanches on this layer have not been reported for a few days, but we feel that it could still be triggered in steeper, unsupported terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 3 - 6