Stormy conditions continue on Saturday. Both natural and human-triggered avalanches are very likely, with the potential for very large avalanches to reach the valley bottom. Travel in avalanche terrain is not recommended, including travel in runout zones.
In the north half of the region, a touchy weak layer is buried near the bottom of the snowpack. This layer has been responsible for many large, destructive avalanches. The likelihood of triggering this layer will be elevated during the stormy conditions on Saturday.
Intense stormy conditions continue, with another 30 to 50 cm of snow possible Friday night into Saturday and strong southwest wind. Touchy storm slabs will be reactive to both human and natural triggers on Saturday. Travel in avalanche terrain is not recommended.
FRIDAY NIGHT: Cloudy with snowfall, accumulation 20 to 40 cm, strong southwest wind, alpine temperature -4 C, freezing level 1500 m dropping to 500 m by the morning.
SATURDAY: Cloudy with snowfall, accumulation 10 to 20 cm in the south of the region and 5 to 10 cm in the north of the region, moderate to strong southwest wind, alpine temperature -10 C, freezing level 700 m.
SUNDAY: Cloudy with snowfall, accumulation 5 to 10 cm, moderate southwest wind, alpine temperature -7 C, freezing level 800 m.
MONDAY: Cloudy with snowfall, accumulation 5 to 10 cm, moderate southwest wind, alpine temperature -7 C, freezing level 800 m.
Many large storm slab were triggered naturally and by humans in the region on Wednesday and Thursday. They occurred within the recent storm snow across the region. In the north of the region, a large avalanche occurred near treeline on the buried weak layer described in the snowpack summary.
Similar avalanche activity is expected to continue this weekend during the stormy conditions.
Intense snowfall continues in the region, forming dangerous avalanche conditions. Storm slab avalanches around 30 to 60 cm thick are widespread and they may overly a touchy weak layer of surface hoar. Thicker slabs will be found near ridges at higher elevations, as the snow is falling with strong southwest wind.
A persistent weak layer is present near the bottom of the snowpack in the northern half of the region (e.g., Duffey, Hurley). The weak layer of sugary faceted grains exists around a hard melt-freeze crust from mid-November, which is an indicative snowpack setup for large and destructive avalanches. The likelihood of natural and human-triggered avalanches on this layer remains elevated with the rapid loading occurring during this stormy period.
