Careful evaluation of avalanche problems is still required when traveling above treeline. At lower elevations, avoid slopes with glide cracks.
Weather Forecast
A weak front tracks across the area today bringing clouds with isolated flurries and trace amounts of accumulation. Alpine high of -2, winds light gusting to 20km/hr and freezing level rising to 1700m. A blocking ridge of high pressure will establish tomorrow, bringing dry and clear conditions with extreme daytime warming by midweek.
Snowpack Summary
~50cm of storm snow combined with sustained SW winds created a slab that is up to 1m deep on lee slopes. This slab overlies a crust on all aspects which provides a good sliding surface. Avalanches may step down to multiple crusts in the top meter. Overnight refreeze created a surface crust at lower elevations that is insulating ~40cm of wet snow.
Avalanche Summary
Warm temperatures brought several small loose wet releases as well as a very large glide crack release (size 3.5). On Friday, a group of 5 accidentally triggered a size 3.0 avalanche on the steep roll on the Thorington line in the Asulkan Valley (NE asp, 2600m, 70m X 100m, 80cm deep on a crust).
Confidence
Freezing levels are uncertain
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.