Archived

Avalanche Forecast

Dec 20th, 2016–Dec 21st, 2016

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

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

Regions: South Coast.

The last few days' new snow sits on a variety of potential weak sliding layers. As the storm snow settles in the coming days, it will be critical to evaluate the bond between new and old snow layers.

Confidence

Moderate - Track of incoming weather systems is uncertain

Weather Forecast

Wednesday: Isolated flurries/ Moderate to strong southwest wind / Alpine temperature 0Thursday: Flurries, accumulation 10-15cm / Moderate southwest wind / Alpine temperature 1Friday: Cloudy with some sunny periods / Light north wind / Alpine temperature -3

Avalanche Summary

There are no new recent reports of avalanche activity, however I would suspect there to be continued potential for skier and rider triggering with the recent new snow, strong winds at upper elevations and a possible weak bond at the storm/old snow interface. There was natural avalanche cycle Sunday night into Monday morning with avalanche releases up to size 2. Reports indicated that avalanches to size 1.5 were being easily triggered with ski cuts.

Snowpack Summary

Up to 60cm new moist or wet new snow overlies the variable old snow surface from late last week, which includes well settled snow on southerly aspects, loose snow on shaded aspects, isolated pockets of surface hoar, and sun crusts on steep southerly aspects. With the potential for buried surface hoar means storm snow weaknesses from this latest storm will take longer than normal to stabilize. An old rain crust is reported to be down 150 cm in the North Shore mountains. This layer is still failing on snowpack tests, but is likely difficult to trigger in most places now.

Avalanche Problems

Storm Slabs

Moist new snow combined with moderate to strong southwest winds have created slabs on top of a variety of potential weak sliding layers.

Be cautious as you transition into wind affected terrain.Avoid freshly wind loaded features, particularly in steep terrain.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 2