Continual snowfall, cool temps and light winds are making excellent ski conditions. The snowpack is adjusting well to the additional snow and conditions are good - but with three weak layers in the upper snowpack, we are waiting for a tipping point.
Weather Forecast
Continued snowfall expected through Thursday with another 10-15 on the ground by the end of the day Thursday. Temperatures will remain cool and winds moderate from the SW. Basically the same weather pattern will persist for the next few days.
Snowpack Summary
50cm of snow has fallen in small increments over the past 8-days creating a lot of loose snow on the surface. Alpine winds have distributed this into leeward areas but only at the highest elevations. Three persistent weak layers lurk in the upper half of the snowpack: Jan 16 down 25cm; Jan 6 down 40cm; Dec15 down 55 cm giving easy-mod test results.
Avalanche Summary
No new avalanches reported or observed, but people continue to get lots of whumphing and settlement cracks - a definite indication of instability. But . . . no significant avalanches.
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.