Flurries and wind continue add and build slabs. The deepest and most reactive deposits will be in the alpine and treeline, around ridge features and steep rolls.
Added flurries and wind will continue to develop slab properties and redistribute loose snow. The deepest and most reactive deposits will be in the alpine and around ridges and lee features at treeline.
Wednesday Night: Cloudy with isolated flurries, trace to 5 cm. Alpine temperature -5 C. Southwest wind 25-35 km/hr.
Thursday: Cloudy and scattered flurries, trace to 10 cm. Alpine temperature -5 C. South wind 25-45 km/hr.
Friday: Cloudy and scattered flurries, 5-15 cm. Alpine temperature -5 C. South wind 20-40 gusting to 60 km/hr.
Saturday: Cloudy with isolated flurries, trace accumulation. Alpine temperature -7 C. Southwest wind 20-40 km/hr.
Further east of the Northwest Inland region, a natural wind slab avalanche cycle to size 2.5 in alpine and tree line areas was triggered by intense wind loading sometime between Tuesday and Wednesday.
A natural avalanche cycle to size 2.5 occurred Tuesday in the neighboring Northwest Coastal region. This area received higher precipitation amounts (30-60 cm) this week, but similarities in the storm suggest a potential for human triggered storm/wind slabs in the Northwest Inland region as well.
Snowfall blanketed 15-30 cm snow around the region early this week. The new snow likely covered a weak layer of surface hoar and/or a crust on south-southwest aspects. Strong south-southwesterly winds have developed wind slabs, especially around ridge features and into the alpine.
Reports suggest there are 2 buried layers of surface hoar in the upper snowpack - one down 15-25 cm below the new snow, and another down 25-40 cm below older, recent snow. Where wind has scoured the snowpack, a crust from November is at or near the surface. In leeward terrain, a this crust is 40-60 cm deep, and may include surface hoar in sheltered openings up to treeline.
Older crusts can be found deeper in the snowpack and are generally breaking down and bonding. Snowpack depths rang from 100-180 cm around treeline, with depths diminishing rapidly below 1500 m and where the wind has scoured. In areas with a relatively thin snowpack, the base of the snowpack likely consists of weak faceted grains.
