Avalanche Forecast

Issued: Mar 5th, 2016 9:04AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Deep Persistent Slabs.

Avalanche Canada jlammers, Avalanche Canada

Recent snowfall amounts vary greatly across the region with the highest accumulations falling in the southwest of the region. Pay close attention to how much new snow fell in your riding area as this will affect your local Avalanche Danger.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

On Sunday expect 3-5cm of new snow with another 3-5cm falling on Sunday night. A mix of sun and cloud is forecast for Monday and Tuesday. Winds should be extreme from the southeast on Sunday, easing to mainly light to moderate from the south on Monday and Tuesday. Freezing levels should sit at about 1200m on Sunday, and then drop to about 1000m for Monday and Tuesday.

Avalanche Summary

On Wednesday, a size 3 deep persistent slab avalanche was accidentally triggered by a skier in alpine terrain in the north of the region. To our knowledge, nobody was injured in the incident. The slab, which ran on basal facets, was up to 200cm deep, 200m wide and 500m long. There have been a handful of recent similar avalanches triggered on basal facets in the mountains north of Kispiox. On Friday, a widespread round of storm slab activity to size 2 was reported from the southwest corner of the region where recent storm accumulations were the greatest. Of note, a size 3 natural storm slab avalanche was also reported from the Howson Range area on a steep, north-facing alpine slope.

Snowpack Summary

On Friday and Friday night, 5-20cm of new snow fell with the highest accumulations occurring in the southwest of the region. Strong winds shifted the new snow into new wind slabs at treeline and in the alpine adding to an ongoing wind slab problem. A layer of surface hoar from early January can be found in isolated locations between 60 and 140cm down. There hasn't been any activity reported on this layer for a couple of weeks now and it is becoming less of a concern. In shallower areas the snowpack sits on a weak base layer of facetted snow. Recently, this layer has been active in the north of the region, responsible for several large avalanches in unsupported alpine terrain.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow and wind has created fresh wind slabs at treeline and in the alpine. Watch for triggering in the lee of ridgecrests and terrain breaks.
Be aware of the potential for wide propagations due to the presence of hard windslabs.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
A layer of facets close to the ground remains a low probability/high consequence concern for most of the region. However, in the north it is more active and has been responsible for several recent large natural and skier triggered avalanches.
Be aware of thin areas that may propogate to deeper instabilites.>Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

3 - 5

Valid until: Mar 6th, 2016 2:00PM