Confidence
Fair - Timing of incoming weather is uncertain on Tuesday
Weather Forecast
Very strong southwest winds are forecast to build overnight Monday. Heavy snowfall is expected to begin mid-morning on Tuesday. Westerly upslope areas should get 20-30 cm during the day on Tuesday and the freezing level should rise to about 900 metres. Snow is expected to continue overnight into Wednesday morning and then become flurries as winds moderate in the afternoon. Some lingering flurries should continue on Thursday as a ridge of high pressure moves into the region.
Avalanche Summary
Some whumpfing reported from ridgetops and southerly aspects that have been wind pressed. Some naturals up to size 2.5 on north and east aspects in the alpine.
Snowpack Summary
The new storm has developed a thick blanket of dry light snow above the cold dry surface. If this new storm warms up a bit, expect a storm slab to consolidate above this cold relatively weak layer. Watch for new windslabs developing due to forecast strong southwest winds. Some surface facetting during the recent cold spell. Strong temperature gradient in the top 30 cm. Stiff windslabs have developed in the alpine and at treeline. Some areas reporting a crust that is now buried by about 50 cm of cold dry light snow. Strong well settled mid-pack. Cornice structures are weak and have been growing fast, and falling off!
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.