Regions
South Coast Inland.
The incoming storm will form new wind slabs and increase the avalanche danger at higher elevations.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
SUNDAY: Flurries starting in the afternoon, moderate southeast winds increasing throughout the day, alpine temperatures around -10.MONDAY: Flurries continuing overnight with 5-15 cm of new snow in the north and 20-30 cm in the south, moderate south west winds with strong gusts, alpine temperatures around -5.TUESDAY: Cloudy with scattered flurries and 5-10 cm of new snow, light winds, alpine temperatures around -12.
Avalanche Summary
No new avalanches were reported on Saturday, but be on the lookout for isolated wind-loaded pockets where wind slabs may still be lingering. Expect avalanche activity to increase with the incoming storm.
Snowpack Summary
Up to 5 cm of new snow covers a variable surface with a mix of soft wind slabs, hard wind slabs, sastrugi, faceted snow, sun crust, and even some surface hoar. Last week's winds were primarily from the north, which reverse loaded many terrain features and formed stubborn wind slabs. For low snow areas, such as the northern part of the region, two layers of concern exist. One is a weak layer of snow from mid-December buried approximately 50 cm deep and other is an old rain crust from November buried 80-120 cm deep. Snowpack tests indicate these layers may be possible to trigger in shallow snowpack areas. Elsewhere, these layers are typically much deeper and are considered to be 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.