We emerge from the latest storms and avalanche cycle with a bit more confidence in the snowpack but are still wary of high elevation and shallow snowpack areas. Surface crusts have hurt the ski quality below treeline.
Weather Forecast
Warming up and strong SW winds for Fri with a strong temperature inversion. Clouding over with temperatures dropping to the minus teens range for Saturday. Winds will drop off on Sunday becoming light from the NE. A trace of snow on Saturday and Sunday but not more than a few a few centimeters.
Snowpack Summary
The 25 to 50cm storm slabs are now capped by a variety of crusts below treeline and on solar aspects and have been influenced by variable winds. The Dec 13 crust is now 60 to 120cm deep and continues to produce planar shears within the facets above the crust.
Avalanche Summary
Warm temperatures and strong winds induced a widespread cycle of storm slabs on all aspects and elevations Wednesday. Some of these events ran from ridge crest to valley bottom however with our first look around today we saw no evidence of activity on the persistent weak layer. There have however, been reports of activity on the PWL from neighbors.
Confidence
Due to the number of field observations
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.