Avalanche Forecast

Moderate -

SUNDAY NIGHT: 5-15 cm of snow, strong to extreme wind from the southwest, freezing level around 700 m.MONDAY: Steady flurries with localized accumulations of 10-20 cm, extreme wind from the south, freezing level steady around 800 m, alpine high temperatures around -3 C.TUESDAY: Another front approaches and brings 20-35 cm of snow, strong wind from the south, freezing level steady around 700 m, alpine high temperatures around -3 C.WEDNESDAY: 15-30 cm of snow, strong wind from the south, freezing level dropping to 500 m, alpine high temperatures around -5 C.

A few size 1-2 natural avalanches were reported in steep terrain features on Saturday in the Shames and Terrace area. Some larger natural avalanches were reported in north-facing terrain on Friday, and explosives have produced large (size 2-3) avalanches in the storm snow throughout the week.There have been several reports of skiers in the Shames area feeling large settlements in low angle terrain (whumpfs), a sign that the storm slabs would be very reactive to human-triggering in steeper terrain.Harsh weather conditions have limited observations over the past week, but with the enormous amount of snowfall there have likely been several cycles of natural avalanche activity.

The onslaught of storms continues with another 15-30 cm of new snow possible by the end of the day on Sunday. Both snowfall amounts and wind effect will be more pronounced near the coast.A total of 100-150 cm of recent storm snow sits above a layer of potentially weak snow that formed during the dry spell in early December. The layer is composed of weak surface hoar or facets that are often found above a crust. The surface hoar is most likely on sheltered slopes at treeline while surface faceting was probably more widespread. Reports from the Shames area on Saturday suggest the storm snow could still be bonding poorly to this layer (as indicated in snowpack tests and whumpfing).Deeper in the snowpack, there are reports of several crusts including an early season crust with facets near the bottom of the snowpack.