Confidence
Fair - Timing of incoming weather is uncertain on Sunday
Weather Forecast
Sunday: Moderate to locally heavy snowfall developing late in the day and continuing overnight / Strong southwest winds / Freezing level at 1000mMonday: Light snowfall / Light west winds / Freezing level at 1000mTuesday: Mix of sun and cloud with snow developing in the afternoon / Light south winds / Freezing level at 800m
Avalanche Summary
Size 2.5 natural cornice falls triggered slabs on north and southeast alpine features in the Duffey area. A size 2 slab was also ski cut on a north aspect at treeline. There were no other reports of avalanche activity from the region.
Snowpack Summary
Moderate to heavy snowfall has been redistributed into potent wind slabs at treeline and above and may overlie small surface hoar buried on February 20th. Where it exists, the surface hoar will likely prolong the reactivity of the new storm slab.On shaded slopes up to 50cm of snow may overlie surface hoar which was buried on February 12th. Most reports of this layer are coming from the Duffey Lake area where recent snowpack tests have shown sudden planar fracture characteristics at this interface. On solar aspects and at lower elevations recent accumulations overlie a melt freeze crust.The mid and lower snowpack pack layers are generally well settled.
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.