Northwest Coastal

A bit of new snow won't add much to our wind slab problems, but it might make recently formed slabs trickier to see. Choose a supported line and treat lee slopes with extra caution.

Wednesday night: Cloudy with scattered flurries bringing 2-5 cm of new snow. Light west winds.Thursday: Decreasing cloud with continuing isolated flurries finishing with a trace to 3 cm of new snow. Light northwest winds. Alpine high temperatures around -5.Friday: Sunny. Moderate to strong northeast winds, increasing over the day. Alpine high temperatures around -10, cooling over the day.Saturday: Sunny. Moderate to strong northeast winds, easing over the day. Alpine high temperatures around -15.

High -

Reports from Wednesday showed explosives control yielding mainly small (size 1) wind slab releases in the Shames area. Several other recent small (size 1.5) natural wind slab releases were observed in alpine features in the Legate Peak area.Tuesday's reports showed more limited wind slab reactivity, with one smaller (size 1.5) wind slab triggered with a ski cut.Reports from Monday included several small (size 1.5) remote triggered (triggered by a skier at a distance) wind slabs on north aspects at around 1500 metres. Slab depths were 20-25 cm and they had failed on the crust buried beneath our recent storm snow.Wind slabs were also reactive to skier traffic over the weekend, generally producing small avalanches. See here for an example.

Strong northeast winds have redistributed up to 40 cm of recent storm snow, creating wind slabs in lee and cross-loaded terrain features. Recent cold temperatures have been transforming surface of this snow into a lower-density layer of faceted (sugary) grains at all elevations. Collectively, this wind-affected and faceting storm snow overlies previously wind-affected surfaces in the high alpine and a thick melt-freeze crust at and below treeline.In the south of the region, the remainder of the snowpack is well-settled.Around Bear Pass and in the north of the region, there is a weak layer of feathery surface hoar crystals about 50 cm deep. This weak layer is likely most prominent in sheltered and shaded areas. Also in the north, a few weak layers may still exist within the middle and lower half of the snowpack. These include another layer of surface hoar around 70 to 100 cm deep and a weak layer of sugary faceted snow around 200 cm deep.