Be cautious of reactive deposits of fresh snow around ridges and in lee terrain. As the sun shines and the snowpack turns moist, the likelihood of triggering loose wet avalanches will increase, especially in areas with fresh snow.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain
Weather Forecast
MONDAY NIGHT: Mostly clear / west wind, 10-15 km/h / alpine low -4 C / freezing level valley bottom TUESDAY: Cloudy with sunny periods and isolated flurries, trace accumulation / southwest wind, 20-40 km/h / alpine high 0 C / freezing level 2000 mWEDNESDAY: Mainly cloudy with isolated flurries, trace to 5 cm snow accumulation / southwest wind, 25-55 km/h / alpine high +1 C / freezing level 2100mTHURSDAY: Cloudy with wet flurries, 5-20 cm / southwest wind, 20 gusting to 40 km/h / alpine high +3 C / freezing level 2500 m
Avalanche Summary
On Sunday, a skier triggered a size 1.5 wind slab avalanche on a steep convex roll at 2150 m and explosives triggered a size 2 storm slab avalanche at 2350, both avalanches occurred on a northeast aspect. A natural avalanche Sunday was also observed north aspect at 2300 m. The size 2 storm slab avalanche failed on surface hoar likely buried early April. This isolated layer may see increased stress as winds redistribute snow and add load or temperatures penetrate the snowpack.Late Saturday, storm snow was sloughing in steep terrain with skier traffic and gaining cohesion.
Snowpack Summary
20-30 cm fell around the region since Saturday, south and westerly winds have produced isolated pockets of windslab around ridge crest and lee features. The new snow accumulated over a melt freeze crust on most aspects. On north-facing terrain above 2000 m, the new snow accumulated over another 20-30 cm wind-affected snow from early April, in isolated areas surface hoar may now be buried 50-65 cm. Older wind slabs sitting on surface hoar might still be sensitive to human triggers. Below treeline snow is disappearing rapidly. Sun and rising freezing levels are warming the snowpack and settling new snow, the likelihood of loose wet avalanches will increase as heat penetrates into the snowpack.
Problems
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.
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.