Archived

Avalanche Forecast

Mar 15th, 2012–Mar 16th, 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

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.

Confidence

Fair - Due to variable snowpack conditions

Weather Forecast

Friday: Light snowfall - light southwest winds - freezing level at 800m Saturday: very light snowfall with a chance of intermittent sun - light and variable winds increasing in the evening freezing level at 600m Sunday: scattered cloud - light and variable winds - freezing level at 500m

Avalanche Summary

Sluffing in steep terrain was observed on Wednesday. Observations from the region have been very limited.

Snowpack Summary

Moderate amounts of low density snow sit over a variety of old surfaces that include widely distributed hard wind slabs, or melt freeze crusts that exist on most aspects below 1000m and on solar aspects as high as 1600m. In exposed areas the newer snow has been shifted into deeper pockets of soft wind slab. The mid February persistent weak layer interface, comprised of spotty surface hoar, facets and crusts, is buried approximately 80cm below the surface. No recent activity has been reported on this interface, but it should still be on your radar, particularly in steeper, unsupported terrain. Cornices in the area are also reported to be very large and primed for triggering.

Avalanche Problems

Wind Slabs

New wind slabs are forecast to develop below ridgecrests, in gullies and behind terrain features.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 3

Cornices

Large cornices exist in alpine terrain. A failure could be destructive by itself, and could also trigger an avalanche on the slope below.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 5

Persistent Slabs

The likelihood of triggering persistent layers buried in early February is greatest on steep, unsupported terrain . Although no recent avalanches have been reported, the chances of triggering may increase with solar radiation forecast for the weekend

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 3 - 5