Direct sun is likely to weaken surface snow layers and give cornices a bit of an extra nudge. Avalanche danger may spike higher than forecast on sun-exposed slopes.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
FRIDAY: Mix of sun and cloud. Treeline temperature near -3. Light winds.SATURDAY: Mainly sunny. Treeline temperature near -1. Light winds.SUNDAY: Mainly sunny. Treeline temperature near -1. Light winds.
Avalanche Summary
On Wednesday, a chunk of falling ice triggered a size 2.5 avalanche. On Tuesday, a few large cornice falls were reported, without releasing large avalanches on slopes below. A few loose wet solar-triggered avalanches were also observed.
Snowpack Summary
Around 20 cm new snow has formed storm slabs and variable thin wind slabs.Persistent weak layers from early January and mid-December are still being reported by local operators. They are generally considered dormant, but could wake up with forecast warming, a surface avalanche stepping down, a cornice fall, or a human trigger in a shallow or variable-depth snowpack area. These layers consist of sun crust, surface hoar and/or facets. Facets linger at the base of the snowpack.
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 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.