Northwest Coastal

Another natural avalanche cycle is expected as yet another storm hits the coast on Tuesday.

High -

MONDAY NIGHT: 5-15 cm of snow, strong wind from the south, freezing level around 700 m.TUESDAY: 15-25 cm of snow, strong wind from the south, freezing level climbing to 1000 m.WEDNESDAY: Stormy weather starting to ease with 5-15 cm of snow, moderate wind from the southwest, freezing level dropping to 500 m.THURSDAY: Cloudy with isolated flurries, light wind, freezing level dropping to valley bottom with alpine high temperatures around -5 C.

Observations have been limited over the past week due to harsh weather conditions, but with the enormous amount of snowfall there have likely been several cycles of natural avalanche activity.Explosives produced several large (size 2) avalanches in the recent storm snow over the past few days. In the Shames area, a few size 1-2 natural avalanches were reported in steep terrain features on Saturday. There have also been a few reports of skiers in the Shames area feeling large settlements in low angle terrain (whumpfs), a sign that the storm slabs could be very reactive to human-triggering in steeper terrain.

The onslaught of storms continues with another 20-40 cm of new snow possible by the end of the day on Tuesday (and rain below 1000 m). Both snowfall amounts and wind effect will be more pronounced near the coast.A total of 100-160 cm of recent storm snow sits above a layer of surface hoar, facets, and crusts that formed during the dry spell in early December. While a concern during the start of the storm, the strength of this layer has probably improved substantially over the past week and it likely requires a heavy load to trigger (e.g. cornice fall, explosives, a small avalanche) . Deeper in the snowpack, there are several crusts, including an early season crust with facets near the bottom of the snowpack.