While deep persistent layers may be stubborn to initiate, the consequences of finding the sweet spot would be substantial. It might not yet be time to ski big open terrain.
Weather Forecast
The ongoing effects of a strong south west flow will continue to give strong SW winds, scattered precipitation and warm temps through Thursday. On Friday the flow begins to shift to more of a weak Westerly, giving clearing skies, tapering winds and cooling temps in to the weekend.
Snowpack Summary
Warm temps have moistened the upper snowpack below treeline. Strong to Extreme SW winds have created hard Wind Slabs and/or sastrugi in all open areas. Faceted layers in the mid and lower snowpack remain a concern, particularly in shallow snowpack areas where facetting is more pronounced and triggering is more likely.
Avalanche Summary
No recent avalanche activity has been observed. A Large (Size 3) Deep Persistent slab avalanche was observed in Alpine terrain last Friday, at 2250m on a North aspect. Triggered by a small Wind Slab hitting a shallow spot, this propagated across the slope into the adjacent deeper snowpack and was up to 2m thick in places.
Confidence
Due to the number of field observations
Problems
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.