Although persistent weak layers have become less likely to trigger, the consequences of an avalanche could be high. Conservative terrain selection is highly recommended.
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Saturday
Weather Forecast
Saturday night: 5-8cm of new snow / Strong southwest ridgetop winds / Freezing level at about 1500mSunday: Light flurries with possible sunny breaks / Light to moderate ridgetop winds / Freezing level at about 1400mMonday: 8-12cm of snow / Moderate easterly ridgetop winds / Freezing level at about 1300mTuesday: Mix of sun and cloud / Light ridgetop winds / Freezing level at about 1200m
Avalanche Summary
On Thursday there was a widespread round of natural storm slab activity (mostly in the size 2 range with some results to size 2.5) in response to new snow and strong winds. In one case a size 3 persistent slab avalanche was remotely triggered on an east-facing slope at 2230m. This points to the ongoing touchy persistent slab problem in some areas. On Friday, a size 2 wind slab avalanche was ski cut on a west aspect at 1900m. Solar-triggered cornice falls (to size 2.5) and loose wet avalanches (to size 2) were also noted. Some of the cornice collapses triggered wind slabs on the slope below. More wind slab activity is expected with wind and snow forecast for Saturday night.
Snowpack Summary
At treeline and in the alpine, light snow accumulations overlie wind slabs which formed during Thursday`s storm. 60-100cm below the surface you'll find a persistent weak layer comprised of surface hoar, facets and/or a thick crust. This layers seems variably reactive. In other words, it's still really touchy in some places while in other places it's really tough to trigger, and there's not much of a reliable pattern telling us what exact aspects are most suspect. I'd continue to be suspicious of steep, unsupported features at treeline and in the alpine as this layer has the potential for very large avalanches. Below this interface, the snowpack is generally gaining strength. At ridgetop, cornices are huge and potentially unstable.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.