Recently formed thin wind slabs have become reactive at higher elevations. Otherwise the main concern remains the basal weaknesses.
Weather Forecast
Monday should bring a mostly cloudy day with moderate to strong West winds. Very light precipitation is possible and temperatures should reach -9 degrees. Windy conditions will continue through Tuesday. Wednesday and Thursday could see small accumulations of new snow.
Avalanche Summary
One thin wind slab failure was observed today. This size 1.5 avalanche occurred in the past 24 to 48hrs on a SE aspect at 2400m. It was a thin wind slab that appeared to fail on the ground.
Snowpack Summary
5 to 10cm of new snow has fallen in the past 36hrs. Strong to extreme SW winds are redistributing this snow and thin wind slab formation is ongoing in the Alpine and open areas at Treeline. The Dec 13th rain crust remains dominant in the snowpack below 2200m. The November rain crust and facet combo remains a concern deeper in the snowpack.
Problems
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
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.