There is uncertainty with the speed of recovery of the snowpack. Maintain conservative terrain choices while we transition to a cooler weather pattern.
Cornices are large and looming, and storm snow and wind may develop new growth. A large cornice fall can be dangerous on its own, and can also trigger deep slabs on slopes below.
Several persistent weak layers exist in the upper meter of the snowpack. Forecasted precipitation will continue to load these layers.
Mixed precipitation and convective flurries will develop storm slabs forming over a moist surface or melt-freeze crust. Storm slabs will be more reactive where wind has accompanied the storm.
A widespread large natural avalanche cycle of wet loose to size 2.5, and persistent slabs up to size 4. While activity peaked on Wednesday, similar avalanche activity is expected to continue with forecasted precipitation and fluctuating freezing levels.
Read the Forecaster Blog for an opportunity to reflect on this week's widespread avalanche activity.
Mixed precipitation will further saturate the upper snowpack at lower elevations. Convective flurries across the region could accumulate 15 to 20 cm of storm snow, which will bury variable surfaces of a melt-freeze crust or moist snow depending on freezing levels.
Several weak layers in the snowpack remain a concern for triggering:
Facets/surface hoar/crust from early March buried 50 to 80 cm deep,
Facets/surface hoar/crust from mid-February buried 110 to 130 cm deep, and
Facets/surface hoar/crust from late January buried 120 to 160 cm deep.
Thursday Night
Partly cloudy, mixed rain and snow, 3 to 5 cm. 20 to 30 km/h south ridgetop wind. Treeline temperature 0 °C. Freezing level 1800 m
Friday
Cloudy, wet flurries, 10 to 15 cm. 20 to 40 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1700 m.
Saturday
Partly cloudy, isolated flurries 5 to 7 cm. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1700 m.
Sunday
Partly cloudy, isolated flurries 1 cm. 15 to 20 km/h variable wind. Treeline temperatures -2 °C. Freezing level 2000 m.
More details can be found in the Mountain Weather Forecast.
