Avalanche Forecast

Issued: Mar 7th, 2016 8:18AM

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 pmarshall, Avalanche Canada

Strong winds continue leading to a variety of wind affected surfaces in exposed terrain. Look to sheltered terrain for the best riding, and be aware of what is above you.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

TUESDAY: Mainly cloudy with light to moderate snow – 5-10 cm. The freezing level is around 800 m and ridge winds are moderate to strong from the south. WEDNESDAY: Sunny breaks. The freezing level gradually climbs to 1200-1400 m. Ridge winds are light increasing to strong from the SE. THURSDAY: Periods of snow. The freezing level dips back to 800-1000 m and winds are moderate from the S-SE.

Avalanche Summary

One size 3 natural storm slab was observed in the Southwest corner of the region on Sunday. This slide probably occurred 1-2 days earlier. It released on a northeast aspect in the alpine. Last week, a size 3 deep persistent slab avalanche was accidentally triggered by a skier in alpine terrain in the north of the region. 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.

Snowpack Summary

10-30 cm of snow has fallen in the past week with the highest accumulations occurring in the southwest of the region. Strong to extreme ridgetop winds have 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
Ongoing snowfall and strong winds continue to create 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 - 4

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 - 6

Valid until: Mar 8th, 2016 2:00PM