Archived

Avalanche Forecast

Mar 16th, 2015–Mar 17th, 2015

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

1: Low

The avalanche danger rating below treeline will be low

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

1: Low

The avalanche danger rating below treeline will be low

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

1: Low

The avalanche danger rating below treeline will be low

Regions: Northwest Inland.

Now that the storm is over, signs of avalanche danger may be less obvious. Touchy wind slabs are lingering.

Confidence

Poor - Due to the number of field observations

Weather Forecast

A brief clearing is expected on Tuesday, before a Pacific frontal system pushes ashore late that day. Generally light precipitation is expected on Wednesday and Thursday, with the freezing level around 1000 m and winds moderate from the S to SW. The next punch of moisture arrives on Thursday night.

Avalanche Summary

A large and widespread natural avalanche cycle occurred last week and into Saturday. On Sunday, skiers triggered several size 1 storm slabs on steep lee features. Click on the blue dot on the map to see a recent wind slab that may have failed naturally or remotely in Sinclair. It was a thick, hard wind slab on a north aspect. There are likely to more like this lurking.

Snowpack Summary

Anywhere from 20 to 120 cm recent storm snow has been redistributed by winds into soft and hard wind slabs at alpine and treeline elevations (highest storm snow amounts were in the north and west). This overlies various surfaces including old wind slabs, hard crusts, surface hoar, and/or surface facets. At the base of the snowpack, weak facets may be found. Cornices are large and potentially fragile. Below treeline, the snow appears to be in a spring melt-freeze cycle.

Avalanche Problems

Wind Slabs

Wind slabs may be triggered by the weight of a person or sled.

Travel on ridgetops to avoid wind slabs on slopes below.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 4