Recent snow and wind continue to build fresh wind slabs in lee features at treeline and above. Small slabs can still have big consequences if mixed with terrain traps.
Weather Forecast
SUNDAY: Mainly cloudy, light southeasterly winds, and treeline temperatures around -10. MONDAY: Mainly cloudy with light snowfall bringing another 5-10 cm, moderate westerly ridgetop winds, and treeline temperatures around -10. TUESDAY: Mix of sun and cloud, light to moderate northwesterly winds, and treeline temperatures around -15.
Avalanche Summary
A few naturally triggered wind slabs on variable aspects up to size 1.5 have been reported over the past couple days.
Snowpack Summary
10-15cm of recent snow and light to moderate winds have created fresh thin wind slabs in exposed areas at treeline and above. This recent snow has also covered old, thicker wind and hard slabs from previous wind events. The mid-December facet/surface hoar persistent weakness can be found buried 70-120 cm deep and is generally giving hard resistant or no results in snowpack tests. However, we are still receiving occasional reports of sudden results, suggesting that it has to potential to propagate into a large avalanche if triggered, particularly in shallow spots where this layer closer to the snow surface. The lower snowpack is well bonded and features a thick rain crust near the ground.
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.