If Friday night's storm arrives early, the avalanche danger may be higher than posted.
Confidence
Moderate - Timing of incoming weather systems is uncertain on Friday
Weather Forecast
Friday: About 5cm of the new snow with an additional 10-15cm overnight / Moderate southwest winds / Freezing level at 600mSaturday: Mix of sun and cloud / Light southwest winds / Freezing level at 1400mSunday: Mostly clear skies / Light southwest winds / Freezing level at 2300m
Avalanche Summary
On Wednesday the upper snowpack was largely unaffected by explosives control work, but it did produce a few storm slab avalanches to size 1. Ski cutting in the region also produced similar avalanche activity in isolated terrain.
Snowpack Summary
10 to 15 cm of light density snow from Monday night and Tuesday now rests on 20 to 30 cm of slightly heavier snow that fell over the weekend. This snow was redistributed by moderate to strong southeast through southwest winds on Sunday. All of this snow is above the the January 6th crust which is present to at least 2100 m, maybe higher. This crust is reportedly breakable below 2100 m. Below the crust there is about 20 cm of settled moist snow.Up to 100 cm below the surface there is a widespread melt-freeze crust that was buried on December 15th, but this layer has not produced any recent avalanche activity and is trending towards dormancy. Beneath the mid-December crust, the lower snowpack is generally strong and 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.