Avalanche activity has decreased, but the Dec 17 surface hoar continues to surprise people. Keep this layer in mind as you choose objectives and plan your day.
Weather Forecast
Today should be a mix of sun and cloud, with an alpine high of -1 and light SW winds. On Thursday an incoming system will bring increasing cloud and isolated flurries later in the day. Through Friday we may see up to 15cm of snow with strong and gusty westerly winds which will amplify the new snow depth over the surface hoar that is growing now.
Snowpack Summary
A widespread new surface hoar layer is growing to mountain top. There is sun crust up to 2cm thick is present on steep solar aspects. A cohesive slab sits over the Dec 17 surface hoar, which is down 60cm-100cm. Crust/facet layers are present just below the Dec 17 layer with varying thicknesses depending on aspect and elevation.
Avalanche Summary
Sporadic avalanche activity continues. Small, loose solar triggered avalanches have been observed daily and there were two size 2's from North aspects yesterday. Outside the park a skier was caught in a size 2 when the Dec 17 failed on an unsupported roll. On the weekend a size 2 was ski cut on a moraine which failed on the Dec 17 surface hoar.
Confidence
Intensity of incoming weather systems is uncertain
Problems
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.