Wind affected and loose snow have bonded poorly with the rain crust. Approach wind loaded features like ridge crests with caution, and manage your exposure to terrain traps in sheltered terrain where loose snow could run faster and further than expected.
Westerly winds will continue to build wind slabs in the alpine and treeline. Approach ridge crest and wind loaded features with caution. These wind slabs will be most reactive to human triggering where they overlie a thick, smooth rain crust.
15-35cm of low density snowfall sits over a thick and supportive crust, on all aspects below 2400m. Moderate to strong westerly winds continue to redistribute this new snow into deeper deposits in lee features in the alpine and treeline.
Early season crusts sit 20-30cm above the ground. Last week's heavy rain saturated the snowpack and has begun to break down this crust at treeline and below, creating a cohesive lower snowpack.
Snowpack depths range from 10-80 cm at treeline elevations. The snowpack tapers quickly below 1800m, significantly diminished by the rain event.
MONDAY NIGHT: Snowfall tapers into the afternoon, cloudy overnight with flurries possible. Moderate westerly winds. Freezing levels at valley bottom.
TUESDAY: Partly cloudy with no precipitation. Strong northwest winds, freezing levels at valley bottom. Alpine highs of -9.
WEDNESDAY: Snow returns Tuesday night with 10-15cm expected by late Wednesday. Freezing levels rise to 1000m, alpine highs of -5.
THURSDAY: Light snowfall continues, with light westerlies. Freezing levels below 500m.
Several size 1 wind slabs were skier triggered Tuesday Dec 6 and Monday Dec 5 in immediate lees at treeline and above.
On Sunday, small loose dry avalanches were observed out of steep sheltered terrain features. Size 1-1.5 wind slab avalanches were observed in immediate lee features at ridge crest.
Small avalanches will move quickly on the crust bed surface. Be mindful of what is below you, such as cliffs and gullies, especially in steep terrain.
Note there are very few field observations this early in the season. If you venture out into the mountains, please share your observations and/or photos on the Mountain Information Network!
