Up to a foot of new snow has fallen during the past two days. At the upper elevations (above 9,000 feet) recent new snow has accumulated upon a persistent weak layer of faceted snow that formed atop an October rain crust. This weak layer is present on shaded northerly facing terrain. Dangerous slab avalanches could be human triggered on this layer. Avalanches are unlikely below an elevation of 9,000 feet and at the higher elevations on slopes where the October rain crust is absent and recent new snow has accumulated on mostly bare ground. A careful evaluation of terrain and snow structure is essential for safe travel in avalanche terrain.
At the higher elevations pockets of soft slab up to two feet in depth could be human triggered in steep, wind loaded avalanche starting zones. These slabs were formed by southwest to northwest winds and will fail on a weak layer of faceted snow that lies upon a hard crust.
( Discussion is generated from the previous day's afternoon forecast. )Although some snow shower activity and banding continues this phenomenon is on the decrease as a high pressure ridge begins to build in from the west and conditions become dryer. Skies are to remain cloudy overnight and on Tuesday with lingering snow showers. Temperatures will be in the single digits and teens at the higher elevations and in the teens and 20s in the valleys. Winds will be northwesterly at 20 to 25 with gusts to 35 miles per hour and will continue to load on leeward slopes.Dangerous conditions exist at the upper elevations. Poor route selection and/or terrain choices could prove fatal. In steep terrain that is underlain by the facets on rain crust problem layer, large to very large slab avalanches could be triggered by the weight of a single person or release naturally. Remote triggering is a reality and could occur as a result of human presence in an avalanche run out zone. Expert terrain assessment and travel skills are essential for safe travel in avalanche terrain. In isolated areas at the mid elevations this hazard extends down into steep north facing avalanche prone terrain. Storm snow instabilities are a potential concern at the mid and upper elevations in steep terrain where the facet/crust problem layer is absent. Avalanches are unlikely at the lower elevations where the snowpack is still quite shallow. The general avalanche hazard is expected to be CONSIDERABLE at the upper elevations, MODERATE at the mid elevations and LOW at the lower elevations.
