Confidence
Fair - Timing or intensity of solar radiation is uncertain
Weather Forecast
The weather pattern is currently dominated by a strong upper ridge of high pressure giving dry conditions.Saturday: Slightly cooler air is expected to move into this area through the day. Alpine temperatures will become considerably cooler, although still warm in the range of 0 to 5C. Winds are expected to pick up becoming moderate SW by the end of the day. You might see the odd flurry towards the end of the day.Sunday: A cooler day with alpine temperatures around 0C. Winds should become light. Monday: Alpine temperatures once again climbing to +5 or possibly higher. Light winds.
Avalanche Summary
On Thursday a number of small moist wet avalanches were observed on solar aspects. A deeper release was noted associated with explosive control that ran on basal facets size 2.5.
Snowpack Summary
Very warm alpine temperatures have created a moist snow surface. Previous winds have scoured windward slopes and sculpted sastrugi (raised ridges of snow) in exposed areas. Average treeline snowpack depths are around 170 cm. Initially, the bond below the most recent storm snow was reported to be weak and comprised surface hoar, at least in some locations. Recent snowpack tests indicate that this layer has gained strength and it is difficult to find a shear within the top 100 cm of the snowpack.There are two lower layers that professionals area tracking near the base of the snowpack. A facet/crust combo from late November is still giving "sudden" results in compression tests and exists at treeline and alpine elevations. Facets likely still exist at the base of the snowpack, especially in areas where the snowpack was particularly shallow early on in the season. The most likely places you would find this problem is in the alpine in shallow rocky areas.
Problems
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.