We have a reactive surface hoar layer with a 50cm surface slab on top of it. Cooling temperatures and moderate winds will consolidate the surface slab further. Stick to low angle forested terrain. Avoid exposure to overhead hazard.
Weather Forecast
Upwards of 25cm of storm snow are expected in the next 24hrs along with slightly cooler temps and South through Southwest winds in the low end of moderate.
Snowpack Summary
A building surface slab sits on top of the well preserved and widespread Dec 17th surface hoar layer (10-20mm) down 30 to 60cm depending on wind loading. This SH layer sits on top of a rain crust up to 2100m on well settled snow above 2100m. The Dec 9th surface hoar layer is down 80cm in the area. The Nov 9th crust lurks 30cm up from the ground.
Avalanche Summary
Numerous skier triggered and natural avalanches were observed or reported yesterday. Remote triggering of the surface slab from distances greater than 50m were reported. Most of the activity was occurring between 1700-2400m. One reported skier triggered slide propagated over 200m. This avalanche activity should be expected to continue today.
Confidence
Forecast snowfall amounts are uncertain
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.