Incoming wind and snowfall will produce fresh wind and storm slabs. With130cm of previous storm snow available for entrainment, even avalanches that start small could accumulate significant destructive potential as they travel downhill.
Weather Forecast
Thursday: Warming (+6 degrees at valley bottom, 1700m Freezing level), Strong to Extreme SW winds, Periods of snow (Up to 40cm)Friday: Scattered clouds, Flurries, Ongoing wind, slight cooling (High 1).Saturday: Clear, Light Wind, High 0.
Snowpack Summary
Up to 130cm of recent storm snow from last weekend is now available for wind transport. Below this is wind-hardened snow exposed areas, near surface facets in sheltered areas, and a melt-freeze crust below 2000m on solar aspects. The lower snowpack facets remain as a persistent concern and have produced isolated Sudden results in snowpack tests.
Avalanche Summary
A concerning lack of natural activity was observed in the wake of last weekends storm. Most starting zones are still holding up to 130cm of fresh storm snow.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
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.
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.