Confidence
Fair - Intensity of incoming weather is uncertain on Tuesday
Weather Forecast
Expect mostly clear skies on monday with light southwesterly winds and freezing levels at surface.On tuesday light snowfall is forecast with moderate westerly winds and freezing levels remaining at surface.Clear skies should prevail again on wednesday as winds switch to light and northerly with alpine temperatures dipping to -12.0.
Avalanche Summary
Recent observations include several easily triggered size 1 windslabs on lee terrain in the alpine near ridge crests.
Snowpack Summary
The early December dry spell left us with weak, large surface hoar and faceted powder on sheltered shady slopes, and a surface crust on sun-exposed slopes. They are now buried about 30cm down by soft slabs from last week and more recent (friday to saturday night) wind-transported moist snow. With rain occurring up to 1800m over the last few days, some of these weak layers may have dissolved below treeline where a rain crust has now formed creating a potential weak layer for the future. At higher elevations, a cohesive and touchy windslab now exists and still over-rides these weaknesses. The mid and lower snowpack are generally well settled and strong, but faceted at base of the snowpack. Avalanche activity on any basal layers is highly unlikely at this time.Check out the Forecaster's Blog link below for more general snowpack discussion and good advice.
Problems
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.
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.