Expect winds slabs to continue to be touchy to triggering on Tuesday into Wednesday as rain and warm temperatures will continue to build slab properties in the upper snowpack.
Wind loaded features are the primary concern. Watch for wind slabs in sheltered terrain and expect reactivity to be greatest in areas they are sitting over surface hoar.
Strong to extreme westerly winds have likely stripped west facing slopes and deposited snow lower down on north and east facing slopes.
Watch for mid slope terrain features like rollovers. In sheltered terrain slabs may sit over a layer of reactive surface hoar.
On Sunday 1 large avalanche (size 2) was triggered utilizing explosives on a east aspect at 1850 m. This avalanche ran on a surface composed of facets with a crown depth that was on average 40cm deep and ran for 200 meters.
On Friday, wind slabs were reported to size one from natural and human triggers.
If you are heading into the backcountry please consider filling out a Mountain Information Network report.
Strong westerly winds have redistributed recent snow into wind slabs at higher elevations. On south facing slopes wind slab could have formed over a sun crust. A layer of surface hoar down around 30cm can be found in sheltered terrain on all aspects up to 2000m. Reactivity will increase where wind slabs sit over this surface hoar, especially as temperatures increase on Tuesday.
A weak layer consisting of facets and a crust formed in November is now buried around 60cm deep.
In general, the snowpack is quite weak and faceted with average snowpack depths of around 150cm at treeline.
Monday Night
Cloudy with 1 to 5 cm of snow expected, or light rain. Strong southwest winds 80 km/h. Freezing levels remaining at 2000 m. Alpine temperatures of +3 °C.
Tuesday
Wet snow and rain continues with another 1 to 5 mm. Strong westerly winds 80 km/h with the freezing levels remaining elevated at 2000 to 2500 m.
Wednesday
Light precipitation 1 to 2 mm. Light southwesterly winds 10 km/h. Freezing levels are expected to begin to descend to around 500 m near days end.
Thursday
Light precipitation 1 to 2 mm. Light southwesterly wind 10 km/h. Freezing levels are expected to begin to remain below 500 m.
More details can be found in the Mountain Weather Forecast.
