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, alpine temperatures around -4.MONDAY: Flurries continuing overnight with 15-20 cm of new snow by the morning, moderate to strong southwest winds, alpine temperatures around -6.TUESDAY: Cloudy with scattered flurries and 5-10 cm of new snow, light east winds, alpine temperatures around -12.
Avalanche Summary
No new avalanches were reported on Friday. Several small wind slab avalanches were reported earlier in the week, and lingering wind slabs may still be reactive in isolated wind-loaded pockets.
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, and even some surface hoar. Last week's winds reverse loaded many terrain features and formed stubborn wind slabs on a surprising range of aspects. An interface of faceted (sugary) snow and surface hoar was buried on Boxing Day and can be found up to 100 cm deep. Recent observations suggest the snow has bonded well to this interface. Snowpack layers below this interface are also generally well bonded.
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.