Mainly sluffing and thin wind slabs in the alpine until a storm on Sunday brings a bit more snow with warming temperatures.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Flurries for Friday then moderate snowfall on Sunday. Friday: 2-3 cm new snow expected with moderate to strong southwesterly ridgetop winds. Freezing level around 1200 m. Saturday, no snow until the evening; during the day there should be some sunshine, especially in the morning. Freezing level around 1400 m. Sunday: 5-10 cm new snow expected with freezing levels going to around 2000 m. Ridgetop winds gusting to 80 km/h from the southwest.
Avalanche Summary
No new reports of avalanches from the region on Tuesday or Wednesday morning.
Snowpack Summary
Surface hoar has grown on top of 10-20 cm loose dry snow that has been sluffing readily on a thick hard supportive rain crust that extends into alpine elevations. In the alpine, winds have been conducive to blowing this low density snow into thin wind slabs in exposed lee areas. At treeline and below, the near surface crust is effectively bridging triggers from penetrating to deeper persistent weaknesses that formed earlier in the season. However, on alpine slopes above the recent rain line poorly bonded crusts, facets, and/or buried surface hoar may be susceptible to triggers. Professionals are still concerned with a buried crust from November, down 50-70 cm, that could be triggered by large loads.
Problems
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.