Posted danger ratings are for Thursday morning. The avalanche danger is forecast to increase throughout the day and will likely become HIGH by the afternoon.
Confidence
Moderate - Timing of incoming weather systems is uncertain on Thursday
Weather Forecast
Wednesday night: 10-20cm of new snow / Moderate southwest winds / Freezing level at 800mThursday: 20-45cm of new snow / Moderate southwest winds / Freezing level at 800mFriday: Mix of sun and cloud in the morning with 5-10cm of snow falling later in the day / Light and variable winds / Freezing level at valley bottomSaturday: Mix of sun and cloud / Light and variable winds / Freezing level at valley bottom
Avalanche Summary
No new avalanches have been reported. Looking forward, snow and wind forecast for the next few days will likely promote a new round of storm slab activity.
Snowpack Summary
By Thursday morning, up to 20cm of new snow is expected to have fallen. Strong southwest winds are forecast to shift these accumulations into much deeper deposits in high elevation lee terrain. The new snow covers a medley of surfaces which include stubborn wind slabs and wind-scoured exposed crust in the alpine, and soft unconsolidated snow in sheltered areas at treeline and below. About 30 cm below the surface you'll likely find a couple of melt-freeze crusts which were buried in mid-December. These layers haven't produced much in the way of avalanche activity, but could come to life with the additional load of new snowfall, especially in areas where loose facets exist above the crust.Below this, the snowpack is thought to be strong and well settled. Snowpack depths are about 135 cm at the 1100 m elevation with many early season hazards present at lower elevations.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.