Avalanche danger will increase with the incoming storm on Sunday night.
Confidence
Moderate - Timing of incoming weather systems is uncertain on Sunday
Weather Forecast
SUNDAY: Flurries starting in the late afternoon, moderate to strong southeast winds, freezing level rising to 800 m.MONDAY: Flurries continuing with 20-40 cm of new snow by the morning, moderate southwest winds, freezing level around 800 m.TUESDAY: Flurries with 10-20 cm of new snow, light east winds, freezing level dropping to sea level with treeline temperatures around -3.
Avalanche Summary
On Friday, ski cutting produced several loose dry avalanches running size 1 in the new snow and running long and fast. The poor bond between the new snow and the old snow interface could become a problem when the next storm arrives. Expect avalanche activity to increase with the incoming storm.
Snowpack Summary
New snow is expected to arrive Sunday afternoon and bury the 15 cm of settling snow from Friday's storm. Sustained southerly winds are building small wind slabs on north-facing slopes in the lee of exposed features. Friday's snow buried a variable interface composed of faceted (sugary) snow and old hard wind slabs. Recent reports suggest the snow has not bonded well to this interface, which means it could become a sliding layer during the next storm. The mid and lower snowpack are well settled and stable.
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.