Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Regions
South Coast.
Cooling temperatures have formed a thick crust that extends into the alpine. At upper alpine elevations pockets of wind slab may exist and will likely be poorly bonded to the underlying crust.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Tuesday
Weather Forecast
MONDAY: Sunny. Ridge wind light, northwest. Temperature -3. Freezing level 700 m. Alpine inversion.TUESDAY: Mostly cloudy, flurries. Accumulation 5-10 cm. Ridge wind moderate, west. Temperature near -2. Freezing level 600 m. Alpine inversion.WEDNESDAY: A mix of sun and cloud with occasional flurries. Ridge wind light, north west. Temperature near 0 degrees. Freezing level 700 m.
Avalanche Summary
On Saturday, a cornice collapse was the likely cause of a size 2 avalanche on a north facing slope near the West Lion. See here for images and more details. Pockets of thin wind slabs may exist in wind-loaded areas in the high alpine and may be sensitive to human triggers.
Snowpack Summary
Rain at the end of the week saturated snow surfaces and only higher alpine elevations were lucky enough to receive a light cover of new snow. With the arrival of cold temperatures, the upper snowpack has locked up as a firm crust. The average snowpack depth at treeline is 300 cm of well settled snow with no significant layers of concern.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.