It is a good day to make conservative terrain choices. Give recent storm snow a chance to settle and stabilize before considering bigger objectives.
Weather Forecast
A ridge of high pressure will build over the region today. Precipitation will be light, and west ridge-top winds, 15km/h. Freezing levels will remain at valley bottom. Light precip will continue Sunday and Monday, with temperatures rising and freezing levels forecast to rise to 1500 m on Monday.
Snowpack Summary
~60cm storm slab sits on a weak layer of large snowflakes which are reactive in tests. The Dec 8 PWL, which is surface hoar at lower elevations and facets and variable wind slabs at higher elevations, is down ~80cm. The Nov 28 surface hoar, down ~1m. Both layers are showing variable reactivity in snowpack tests.
Avalanche Summary
We have observed natural avalanche activity in the highway corridor in the last 24 hrs. Avalanches are running up to size 3.0 in the storm snow and depositing snow in runnouts. On-going artillery avalanche control is producing few results west of the summit, with results up to size 2.0.
Confidence
Due to the number and quality 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.
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.