Wind effect will drive the avalanche danger in many areas. The safest, and best, riding may be in lower elevation terrain sheltered from the wind.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
Thursday: Clear skies / Strong westerly winds / -13 in the alpineFriday: Clear skies / Strong westerly winds / -16 in the alpineSaturday: Increased cloud / Moderate southwest winds / -11 in the alpine
Avalanche Summary
On Tuesday, numerous naturally triggered wind slabs to size 1.5 were noted in steep, high elevation terrain. Continued strong winds on Thursday should promote ongoing wind slab activity. Although natural avalanche activity will likely taper-off in the coming days, fresh wind slabs will be slower to gain strength with the cooler temperatures, and human triggering will remain a concern in wind-exposed terrain.
Snowpack Summary
Up to 36 cm of low density snow fell on Sunday night and Monday. In some areas, moderate to strong southwest and more recent northerly winds have shifted these accumulations into wind slabs at treeline and above. In deeper snowpack parts of the region, the mid-December facet layer lies up to 120cm below the surface. In these areas professionals feel this layer has generally gained considerable strength. That said, I'd carefully investigate this interface before pushing into steeper terrain, especially in shallower snowpack areas where this weakness may show prolonged reactivity.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.