Recent snow and strong winds have changed the avalanche danger for the first time in weeks. It is time to adjust terrain choices. A significant storm is expected Tuesday night which will further elevate the Danger Level.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
Between 40 and 50cm of new snow is possible on Tuesday night and Wednesday. Strong to extreme SW winds are expected to accompany the snowfall. Temperatures in the alpine will be near -14 on Tuesday.
Avalanche Summary
Widespread loose dry slides up to size 2.0, but averaging size 1.5 ,on all aspects and all elevations. Some minor slab propagations were observed to be triggered by sluffs on steep lee and cross loaded features.
Snowpack Summary
Up to 25cm of storm snow has fallen in the past 48hrs. Storm slabs are present in the alpine and treeline areas as well as open areas below treeline. Some cracking was observed today in the alpine. The surface hoar and surface facets are now buried and are a layer of concern, especially at treeline and below.
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.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.