Archived

Avalanche Forecast

Mar 13th, 2012–Mar 14th, 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

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

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

Regions: Northwest Coastal.

Confidence

Fair - Intensity of incoming weather is uncertain on Thursday

Weather Forecast

Wednesday: light snowfall - moderate to strong southeast winds - freezing level at 600m Thursday: moderate snowfall - moderate and variable winds - freezing level at 900m Friday: light snowfall - moderate southwest winds - freezing level at 600m

Avalanche Summary

Recently loaded wind pockets to size 1 were reportedly ski cut in the region. A size 1.5 cornice failure was also reported.

Snowpack Summary

Continued strong and variable winds have redistributed light amounts of recent storm snow into thin wind slabs that most commonly exist at treeline and in the alpine. In the northern part of the region two persistent weak layers are on the radar of some operators: Surface hoar buried at the beginning of March is as much as 70cm deep. The early February persistent weak layers (surface hoar, facets, crusts) are over a metre down. Although triggering persistent weaknesses has become less likely, persistent slabs would be destructive in nature, particularly below treeline on isolated and sheltered steep terrain where buried surface hoar may be preserved. Cornices in the region are reported to be very large and unstable.

Avalanche Problems

Wind Slabs

Variable strong winds have formed thin wind slabs in unusual places, but generally below ridgecrests and in gullies.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3

Cornices

Cornices are reported to be very large at this time. A cornice fall could be destructive by itself, and may also act as a trigger for the slope below.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 6