Avoid wind effected terrain on leeward slopes. Strong south winds and new snow will build touchy wind slabs throughout the day on Friday.
As the storm builds through Thursday night and Friday new touchy wind slabs will form on northerly aspects. These wind slabs will overlie old hard slabs and wind effected surfaces. Strong winds will mean that wind slab could form further down slope then expected.
Thursday night: a storm arrives bringing up to 10cm of new snow to the White Pass area with moderate to strong winds from the south. Low of -3 at 1100m.
FRIDAY: Stormy weather continues with 10-15cm of snow, strong wind from the south. High of -2 at 1100m.
SATURDAY: Stormy weather continues with 5-10cm of snow. Moderate to strong wind from the south. Freezing level rising to 900m.
Sunday: clearing throughout the day, snow ending around noon. Winds becoming light. High of -12 at 1100m.
On Wednesday our field team observed a size 2 natural wind slab avalanche on a southeast aspect at 1500m.
A few small (size 1-1.5) wind slab avalanches were reported on Tuesday, including a skier controlled wind slab from the AvCan field team. Expect the size and likelihood of wind slab avalanches to increase with the incoming storm.
Open terrain will continue to experience steady blowing snow with the incoming storm. This will further reshape the already variable snow surface with a mix of fresh soft wind slabs, old hard wind slabs, sastrugi, and scoured surfaces. Pockets of soft snow may be found in sheltered trees. Some thin crusts may be found near the surface on south-facing slopes and at lower elevations further inland where there has been recent snowmelt. There are currently no concerns about the lower snowpack, although areas with thin snowpacks have weak faceted snow near the ground.
