Strong winds are driving the alpine danger to CONSIDERABLE. Watch for whumphing and cracking below your feet and continue to make observations while gaining elevation towards alpine terrain.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
Saturday: Mainly cloudy. New snow 5-10 cm accompanied by strong southwest ridgetop winds. Alpine temperatures near -2 and freezing levels 1200 m.Sunday: Mix of sun and clouds. Ridgetop wind strong from the West and freezing levels near 1400 m.Monday: Cloudy with some sunny periods and isolated flurries. Ridgetop wind generally light with strong gusts from the southwest. Alpine temperatures near -4 and freezing levels 1400 m.
Avalanche Summary
On Friday, numerous natural storm slab avalanches were reported from North aspects above 1700 m. I suspect with the strong winds and new on Saturday this problem may persist.
Snowpack Summary
Up to 20 cm of new snow will initially have a poor bond to the plethora of old snow surfaces including a melt-freeze crust on sunny aspects, surface hoar on north aspects above 1600 m and moist snow surfaces below 1600 m. Wind slabs are building on most aspects due to the changing winds and overhanging cornices exist along ridgelines. Deeper in the snowpack, the mid-December and late-November weak layers are composed of crusts and sugary facets, which are down 150-300 cm. These layers are currently dormant.
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.
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.