Continued loading from new snow and strong winds will result in High avalanche danger in the alpine.
Confidence
Poor - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Strong Southwest winds overnight combined with 15-20 cm of new snow and freezing levels rising up to about 1500 metres. Snow ending Sunday morning with a chance of flurries during the day with moderate Westerly winds. 3-5 cm of snow overnight Sunday into Monday morning combined with light Northwest winds. Unsettled with a chance of broken skies during the day on Monday. The next pulse of moisture should hit the coast on Tuesday, models are not in agreement on location and timing or intensity of the next storm.
Avalanche Summary
Explosives control released storm snow avalanches up to size 1.5 and some deeper avalanches that may have run on the November 28th buried crust (Deep persistent weak layer).
Snowpack Summary
A new storm slab is developing above the mix of current surfaces which include a mix of stubborn wind slabs and settled storm snow in the alpine, and a hard rain crust at lower elevations. Surface hoar growth has been reported in sheltered areas. There is still concern for a buried crust/facet layer which formed in November.
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.
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.