Riders could trigger touchy wind slabs at higher elevations.
Strong southwest wind has formed wind slabs in lee terrain features at higher elevations. Storm slabs may also be found in areas protected from the wind. These slabs may be touchiest if they are sitting on a weak layer of surface hoar or faceted snow.
SUNDAY NIGHT: Cloudy with snowfall, accumulation 5 to 10 cm, 40 km/h southwest wind, alpine temperature -5 C, freezing level 1100 m.
MONDAY: Cloudy with snowfall, accumulation 5 cm, 50 km/h southwest wind, alpine temperature -5 C, freezing level 1000 m.
TUESDAY: Cloudy with snowfall, accumulation 5 to 10 cm, 60 km/h southwest wind, alpine temperature -3 C, freezing level 1300 m.
WEDNESDAY: Cloudy with snow and rain, accumulation 5 to 15 cm above 1800 m and rain below, 60 km/h southwest wind, alpine temperature 0 C, freezing level 1800 m.
Many large (size 2) wind slab avalanches were observed on Friday and Saturday, being triggered naturally and by riders (for example, here).
Looking forward, similar avalanches are expected to be triggerable by riders as the slabs continue to form.
Strong southwest wind and continual small amounts of snow have formed wind slabs in lee terrain features at higher elevations. Storm slabs may also be building in sheltered terrain. These slabs may take a bit of time to bond to the snowpack, particularly where they sit on weak faceted snow or surface hoar crystals. The snow tapers with elevations. Below around 1300 m, only a small amount of snow overlies a hard melt-freeze crust. Below around 1000 m, any precipitation is forecast to fall as rain, which will soak a previously wetted snowpack.
Two weak layers may exist around 50 to 100 cm deep in the snowpack. The first is a surface hoar layer from mid-January and the second is a layer of faceted snow from early January. These layers haven't produced recent avalanches, but the potential remains until these layers bond to the snowpack.
