7AM UPDATE: Fresh, reactive storm slabs are building over a weak surface. Buried weak layers in the upper snowpack may remain triggerable.
A weak layer of surface hoar/crust/facets exists in the top 40 cm of the snowpack. While this snowpack structure is concerning, the likelihood of avalanche activity on this layer has been decreasing.
New snow and wind are forming fresh slabs. They may be particularly reactive where they sit over surface hoar or a crust.
Over the past few days, the persistent slab problem has been tested, with mixed results. On Wednesday and Thursday, a couple of natural cornice falls reported from around the region did not trigger slabs on slopes below. Meanwhile, explosive testing on a convex roll at treeline in the Lizard range produced a size 1.5 persistent slab avalanche.
20 to 30 cm of new snow falls over a widespread layer of surface hoar and a crust on solar aspects.
Below this, depending on aspect and elevation, the top 50 cm may contain one or two more layers of crust, facet and/or surface hoar formed in late January and early February. We are uncertain whether these layers will become more or less problematic as they get buried deeper.
The mid and lower snowpack remain well settled, with no significant concerns at this time.
Friday Night
Cloudy. 20 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.
Saturday
Mostly cloudy. 5 to 15 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -5 °C.
Sunday
Mix of sun and clouds. 2 to 4 cm of snow. 30 km/h west ridgetop wind. Treeline temperature -6 °C.
Monday
Mix of sun and clouds. 4 to 5 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -5 °C.
More details can be found in the Mountain Weather Forecast.
