A small avalanche cycle occurred overnight on Saturday with a few paths releasing full depth to ground. Large avalanches are possible at this time of year.
Confidence
High - Intensity of incoming weather systems is uncertain on Monday
Weather Forecast
Convective flurries will likely continue overnight giving us another 5-8cm. Lots of new snow is available for transport and winds are forecast to remain in the 30-40km/hr range. Temps are forecast (-8C in the alpine) to cool and freezing levels will be dropping to more seasonal values (1600m).
Avalanche Summary
There was a small natural avalanceh cycle last evening up to sz 3. Many paths in the northern part of the forecast region ran full path and depth failing on basal facets at the ground. The cycle seems to be over but that commonly means that these areas are ripe for a trigger such as a human. Numerous loose dry avalanches were also observed on all aspects in the alpine out of steeper terrain.
Snowpack Summary
Up to 30cm of snow over the past 24hrs in Alpine terrain. This snow tapers in terms of amounts and the lower elevation areas only have about 15cm. Winds were generally light over the past 24hrs and this new snow has only began to develop isolated windslabs in open wind affected terrain. Gullies, ridgelines, crossloaded areas will be places to be heads up for these problems. If you start to feel that cakey or upside down feeling in the snowpack thats a good indication that you are moving into more wind affected areas. Thin locations are still likely areas wherein you can awaken the basal instabilities causing a full depth avalanche. New windslabs will be reactive to skier traffic for a few days so use caution as you travel and choose smaller slopes to test the stability before committing to the terrain.
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.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
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.