Natural avalanche activity has tapered off, but human triggering is still a real concern. Conservative terrain choices are in order, as the weak basal layers can still produce very large avalanches.
Confidence
High - Timing or intensity of solar radiation is uncertain
Weather Forecast
Thursday will be a mix of sun and cloud with no precipitation. Winds will be out of the West at 25 km/h gusting to 50 km/h. The freezing level is expected to remain at valley floor with Alpine temperatures near -8 C.
Avalanche Summary
No new avalanches were observed today but the places that have not gone look primed to go. The forecasters are still avoiding any exposure to larger slopes overhead. Avalanches that have occurred over the past weak were very large, had wide propagations and failed in the basal weak layers. In many cases these slides have been reaching or exceeding historic run-outs.
Snowpack Summary
Up to 15cm of recent snow overlies a supportive crust layer. Above 2200m this crust begins to deteriorate. In Alpine and Treeline wind slabs are found on all aspects, but expect deeper deposits on lee and cross-loaded features. The lower 125cm of the snowpack consists of facets and depth hoar. This critical weakness will persist for the rest of the season.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.