Archived

Avalanche Forecast

Mar 12th, 2012–Mar 13th, 2012

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

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

2: Moderate

The avalanche danger rating in the alpine will be moderate

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

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: Northwest Inland.

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Tuesday: trace amounts of snow - light to moderate southwest winds - freezing level at surface Wednesday: Very light snowfall - light to moderate south winds - freezing level at 600m Thursday: light to moderate snowfall - moderate to strong south winds - freezing level at 1100m

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

Melt freeze crusts exists on most aspects below 1000m and on many 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

With forecast snow and moderate winds, watch for fresh windslabs on lee slopes Cornices are also large, and if triggered, could initiate avalanches on the slope below.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Persistent Slabs

The persistent weak layer that formed in early February may still exist on unsupported, sheltered slopes at and below treeline . Although avalanches on this layer have not been reported this week, triggering is still possible in isolated terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 3 - 5