Northwest Coastal

Stormy weather will elevate the danger this weekend. Minimize your exposure to avalanche terrain when there's rapid loading from new snow and wind.

Moderate - Timing of incoming weather systems is uncertain

SATURDAY: 10-20 cm Friday night then clearing and cooling throughout the day, strong northwest wind, freezing level dropping back to valley bottom.SUNDAY: The next system arrives Sunday morning delivering 10 cm snow throughout the day and continuing into the evening with another 15-30 cm Sunday night, moderate west wind, alpine high temperatures around -8 C.MONDAY: Clearing throughout the day with isolated flurries, light to moderate southwest wind, alpine high temperatures around -5 C.

Natural avalanche activity was observed on Friday morning, producing several 30 cm thick slabs in the latest snow.A few persistent slab avalanches released on Wednesday, most likely failing on the mid-January crust. This includes a natural size 3 avalanche on a southwest slope at 1150 m near Exstew, a few skier triggered slabs (size 1-2) in thinner snowpack areas (east of Terrace and the northern part of the region). The mid-January layer was also active in the Shames area last Saturday, where a skier triggered a size 2 avalanche on a northeast alpine slope. In this case, the weak layer was composed of surface hoar. Overall, activity on persistent weak layers has been limited recently, but enough to suggest these layers may remain reactive through this current storm.

Fresh snow will continue to accumulate the next few days. In some areas up to a metre of storm snow has already accumulated over the past week. Warm temperatures are promoting the settlement of new snow, while westerly winds are blowing snow around in exposed areas.A weak layer buried in mid-January remains a concern and is now 60-100 cm deep. In most areas this layer is a crust, but it may also be surface hoar in sheltered areas at treeline and below. This layer produced a few human triggered avalanches throughout the region over the past week, and may remain reactive as it adjusts to the weight of the new snow.In thinner snowpack areas (north and inland), deeper crust / surface hoar layers that were buried in December and early January may still be a concern. They are buried over 100 cm below the surface, but may be triggerable from thin spots.