There is uncertainty whether forecast heavy precipitation will come as rain or snow. Certainly where it is all falling as snow, the avalanche danger will be HIGH.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Monday
Weather Forecast
MONDAY: Mix of rain and snow, accumulation 15-20cm overnight Sunday into Monday and another 20cm through Monday / Light to moderate southwest wind / Alpine temperature 1 TUESDAY: Cloudy with scattered flurries / Light to moderate west wind / Alpine temperature 0 WEDNESDAY: Cloudy with scattered flurries / Light west wind / Alpine temperature 0
Avalanche Summary
No new avalanche activity has been reported. Expect to see both storm slab and loose wet avalanche activity on Monday with heavy precipitation coming as a mix of rain and snow.
Snowpack Summary
Cool temperatures through the day on Saturday created a crust on a previously moist or wet surface. Since then 25-40cm of fresh new snow has fallen to bury this crust. Looking down into the snowpack there are a few prominent melt-freeze crusts that were buried mid-December and are now 50 to 100cm below the surface. After heavy rain last Friday penetrated most of the snowpack, these crust layers have been reported to be bonding to the snow above and below. The rain last week has reduced the snowpack depth at 1000m to about 140cm and many early season hazards are still present at
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.