Avalanche Forecast

Issued: Dec 3rd, 2013 8:06AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Persistent Slabs.

triley, Avalanche Canada

Kootenay Boundary.

Clear cold days are hear after the recent storm. The new storm slab is settling slowly with the cold temperatures, and the recently buried weak layers may be slow to bond. Dig down and find out how this slab is bonding in your area.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Cold and clear with Northeast winds for the entire forecast period. The cold arctic air continues to dive South into the weekend.

Avalanche Summary

No reports of natural avalanches releasing after the storm. Storm slab avalanches may continue to be triggered by light additional loads like skiing/riding. Storm slab avalanches that are released may be large and destructive. This storm needs some time to settle and bond, forecast cold temperatures may preserve recently buried weak layers and require more time to settle and bond than when the post storm temperatures are warm. This is a complex avalanche forecasting scenario; complicated by early season timing when we have few observations coming from the field.

Snowpack Summary

The new storm slab is about 40-70 cm deep depending on where you are in the region. Storm slabs are sitting above recently buried weak layers of surface hoar on North aspects and melt/freeze crusts on solar aspects. In some parts of the region, the storm slab may not be well consolidated and may not result in shears from snow-pit tests. There are some reports of a deeply buried early season crust that formed in October, this layer is more likely to be found in the high alpine on northerly aspects.

Problems

Storm Slabs

Storm slabs may continue to be triggered by human activity where the new snow is sitting on a weak layer that was recently buried. Storm snow slabs are up to 70 cm deep and may result in large avalanches if triggered.

The new snow will require several days to settle and stabilize.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 5

Persistent Slabs

The deeply buried early season crust may be reactive to the added load of storm snow, the weight of large triggers like snowmobiles or a group of skiers, or from storm snow avalanches in motion.

Be aware of the potential for full depth avalanches due to deeply buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Dec 4th, 2013 2:00PM