Human triggering of persistent slab avalanches continues to be reported.
Expect to find fresh wind slabs at higher elevations, but buried weak layers remain the primary concern.
Reactive wind slabs likely exist on north and east facing slopes around ridgelines. Small wind slabs could step down to deeper weak layers producing very large avalanches.
Avoid areas where the snowpack thins, like steep, rocky start zones at treeline and alpine elevations. Weak layers are more easily triggered here.
A large human triggered persistent slab was reported on Saturday from a steep alpine slope. Cornice falls were also reported to be triggering slab avalanches on the slope below.
Previous in the week, large to very large slab avalanches were triggered naturally and by explosives, size 2 to 3.5. Primary concern is for further activity on these buried weak layers, producing large avalanches.
Up to 20 cm of snow is expected by Monday afternoon, accumulating over a crust on sun affected slopes, surface hoar in sheltered terrain, and wind affected snow in exposed areas. Storm snow is not expected to bond well with the old snow surfaces below.
A widespread crust with weak facets above remains a concerning layer for human triggering. Buried 80-150 cm deep, this layer has produced very large avalanche activity this week.
The snowpack below the crust is generally strong.
Sunday Night
Cloudy with up to 15 cm of snow expected. 30-50 km/h southwest winds. Freezing levels remain around 1200 m.
Monday
Cloudy with another 5 cm possible. 40-60 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1500 m.
Tuesday
Cloudy with up to 10 cm of snow. 30-40 km/h southwest ridgetop wind. Treeline temperature -4 °C. Freezing level 1500 m.
Wednesday
A mix of sun and cloud with isolated flurries. 10-20 km/h southwest ridgetop wind. Treeline temperature -3 °C. Freezing level 1600 m.
More details can be found in the Mountain Weather Forecast.
