Have a cautious mindset heading into this weekend. New snow is expected to bond poorly to an atypically weak surface formed by recent cold temperatures.
As new snow and wind arrive on Saturday afternoon, fresh reactive wind slabs may form in exposed areas.
Variable winds have redistributed recent storm snow into stiff pockets of wind slabs. Winds today will be from the southwest, whereas previous wind slabs formed in a reverse loading pattern due to northeast winds. Be sure to assess the snow surface on any aspect you are travelling on for clues of wind effect, like cracking or hollow drum-like sounds.
On Thursday, a size 1 skier-triggered wind slab occurred on a south aspect in the alpine on Pump Peak. This avalanche slid on a crust and was likely a result of recent northerly outflow winds.
Looking forward to Saturday, snowfall and increasing southwesterly winds may form small but reactive wind slabs by the end of the day. Riders should be aware that stiffer and less reactive slabs may linger in lee and cross-loaded areas from previous strong northerly outflow winds.
New snow at upper elevations from early in the week has accumulated over a variety of old surfaces including wind slabs in the alpine and a breakable freezing rain crust between 1100 m and 1600 m. In sheltered areas, surface faceting due to cold temperatures and/or soft surface snow remains.
The mid and lower snowpack is well-settled, strong, and consolidated.
Snowpack depths are reaching 250 cm at treeline.
Friday night
A mix of sun and cloud. Alpine temperatures around -9 °C. Ridge wind light to 15 km/h from the northwest. Freezing level at valley bottom.
Saturday
Cloudy with snowfall intensifying in the evening, 5 cm accumulation by end of day. Alpine temperatures reach a high of -5 °C. Ridge wind southeast 20 km/h gusting to 50 km/h. Freezing level 300 meters.
Sunday
A mix of sun and cloud with flurries, up to 10 cm accumulation. Alpine temperatures reach a high of -3 °C. Ridge wind southwest 20 km/h to 45 km/h, easing in the afternoon. Freezing level 700 meters.
Monday
Cloudy with sunny periods and isolated flurries. Alpine temperatures reach a high of -2 °C. Ridge wind southeast 20 km/h gusting to 50 km/h. Freezing level 900 meters.
More details can be found in the Mountain Weather Forecast.
