Northwest Coastal

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Poor - Due to the number of field observations

Synopsis: An arctic ridge of high pressure will persist over the BC Interior and Yukon for the next several days. The outflow winds through the coastal valleys and inlets will become very strong overnight Thursday and Friday as the arctic air deepens in the interior.Friday: Mainly sunny with extreme outflow winds in the valleys and moderate to strong northeasterly alpine winds. Treeline temperatures expected to be around -10. Saturday: Mainly sunny with some thin cloud possible, outflow winds easing moderate in valley bottoms and light to moderate northeasterly alpine winds. Treeline temperatures expected to be around -15 but not much colder in the alpine. Sunday: Continued clear, windy, and cold with the possibility of above freezing temperatures between 1200m and 2000m.

Recent observations near Shames include a few natural wind slab avalanche up to Size 3 in steep lee and cross-loaded terrain from northerly outflow winds.

Recent storm snow is settling and gaining strength, however weaknesses at the old snow interface down approximately 40cm may still need time to heal. In the Shames area on Sunday a layer of preserved stellars at this interface was giving easy to moderate, but sudden planar compression test results. More recently, compression tests on a wind-loaded slope gave easy sudden collapse results in a layer of soft snow under a hard wind slab. Snowpack depths near treeline are highly variable but around a metre in sheltered areas. The lower snowpack is a series of crusts, some of which are laminated with facets, particularly in shallower areas. Facets under the uppermost crust, down approximately 50cm, gave hard sudden collapse compression test results in the Shames area on Sunday. Surface hoar is growing on sheltered slopes, and sun crusts may be forming on steep, low-elevation south aspects.