While natural avalanche activity is slowing down, the snowpack is still adjusting to it's new load. Skier triggering remains likely.
Weather Forecast
Unsettled conditions are expected to continue. Light to moderate precip is expected today, possibly depositing up to 10cm of snow. Freezing levels will remain around 1300m, with moderate-strong SW winds. Overnight, temps should cool with freezing levels lowering to valley bottom. Light flurries and moderate W'ly winds are expected through Monday.
Snowpack Summary
Dense snow was rapidly deposited on a reactive layer down 55-65cm, which consists of a variety of surfaces including small surface hoar and crust. The storm snow is wet below 1650m and moist to 2000m. At treeline and above, sustained winds have further loaded slopes and formed windslabs. A surface hoar layer down 1.2m continues to be monitored.
Avalanche Summary
Natural avalanche activity tapered off yesterday, following this weeks widespread cycle. During the week, numerous avalanches were observed running to valley bottom with many in the size 3.5 range. Cracking was reported yesterday when ski cutting steep, supported rolls. A slab avalanche 65cm deep was triggered by loading snow. The debris was 1.5m.
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.
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.