New snow and strong winds are expected to build storm slabs on the recent rain crust. Be extra cautious in leeward areas where wind-deposited, "pillowy" snow maybe present.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
As much as 10-15 cm of snow is forecast for Sunday night along with strong strong winds and lowering freezing levels.Monday: Mix of sun and cloud. Strong west wind. Alpine Temperature -5. Freezing level 1000 m.Tuesday: Flurries. Accumulation 5-10 cm. Moderate to strong southwest wind. Alpine Temperature -5. Freezing level 1100m.Wednesday: Mix of sun and cloud. Moderate to strong west wind. Alpine temperature -5. Freezing level 1100m.
Avalanche Summary
Large loose, wet avalanches were reported during last week's rain event. With the arrival of cooler temperatures on Saturday, reports indicate that the snow surface has refrozen and no new avalanche activity has been reported. As snow and wind load the old surface expect to see an increase in activity in the new storm snow.
Snowpack Summary
Approximately 5 cm of moist snow overlies the crust that formed following the rain event on November 23rd. The crust is up to 10 cm thick and extends to mountain top elevations on all aspects. The snowpack below the crust is moist to ground. Rain has washed away much of the snow below treeline and in many areas there is not enough snow to produce avalanches.
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.