Archived

Avalanche Forecast

Mar 11th, 2012–Mar 12th, 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 limited field observations

Weather Forecast

Monday: Up to 10cm of new snow - moderate to strong easterly winds - freezing level at surface Tuesday: Light snowfall - light to moderate southwesterly winds - freezing level at surface Wednesday: Light snowfall - moderate southeast winds - freezing level rising to 600m

Avalanche Summary

No new avalanches to report. We'd love to hear about what you've seen in the field. Any observations can be sent to: [email protected].

Snowpack Summary

Warm temperatures and then subsequent cooling have created crusts on all aspects below 1000m and on sun-exposed slopes as high as 1600m. More recently, intense wind-loading and light snowfall accumulations have taken place with snow surfaces either getting scoured or packed into hard wind slabs. 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 has been responsible for larger avalanches that occurred last week. This layer should be on your radar, as it may be susceptible to rider triggers.

Avalanche Problems

Wind Slabs

Forecast strong winds and new snowfall will continue to form fresh wind slabs, generally below ridgecrests, behind terrain features and in gullies. Cornices are also large and weak, and could trigger wind slabs on the slope below.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 4

Persistent Slabs

The persistent weak layer that formed in early February 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 by skiers and riders.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 3 - 6