Avalanche Forecast

Moderate -

The cold Arctic air is expected to persist for a few more days and weather models are currently showing a storm system for Saturday night. On Thursday, mostly sunny conditions are expected with treeline temperatures around -15C. A temperature inversion currently exists and temperatures at valley bottom are colder than at higher elevations. Alpine winds are expected to become strong from the northeast by Thursday afternoon. Similar conditions are expected for Friday with sun, treeline temperatures around -15C, a temperature inversion in the valley, and moderate to strong outflow winds. On Saturday, models are currently showing increasing cloud cover, warming temperatures, and winds switching to the northwest. Substantial precipitation is currently forecast for Saturday night.

No recent avalanches have been reported in this region. If the winds increase on Thursday, new wind slab formation is possible in exposed terrain. The mid-November surface hoar layer may still be reactive in isolated areas and is creating a low probability, high consequence problem.

Clear skies and strong outflow winds have created a variety of snow surfaces including scouring and hard wind slabs in exposed areas. Faceting of the upper snowpack and surface hoar up to 12 mm has in reported in sheltered areas. Strong easterly winds over the past week have created wind slabs on aspects you may not expect them. Wind slabs could be present on all aspects in open areas at treeline and above. A layer of surface hoar which was buried mid-November is down 60-120 cm in many parts of the region. This layer may be reactive to human triggers in isolated locations or could be triggered by a smaller avalanche that steps down to this layer. Treeline snow depths are around 140-200 cm in the Terrace and Stewart areas, but substantially less further north. Concerns in the north are basal weaknesses that may exist in the shallower snowpack areas especially on smooth alpine features like glaciers.