Danger could INCREASE TO CONSIDERABLE with intense radiation on south and west aspects, especially at treeline and below. Be aware of how the warm weather is changing the snowpack.
Confidence
Good - Timing or intensity of solar radiation is uncertain
Weather Forecast
The weather pattern starts to change as the dominating upper ridge weakens allowing a more onshore flow, bringing cloudy skies and light precipitation.Tuesday: Mix of sun and clouds. Alpine temperatures near 2.0 and freezing levels riding to 2500 m. Ridgetop winds will blow light from the West.Wednesday/Thursday: Mainly cloudy with light precipitation amounts. Alpine temperatures near 2.0 and freezing levels around 2200 m. Ridgetop winds light from the West.
Avalanche Summary
On Monday, numerous wet slab avalanches and glide crack releases were reported up to size 3 from South-West aspects.
Snowpack Summary
We are in a classic spring melt-freeze cycle. The surface snow becomes moist up to 2200m on all aspect and to ridgecrest on south and west facing slopes. Large cornices looming cornices threaten many slopes below. Surface hoar growth and surface facetting is happening at night on high sheltered, northerly aspects. A buried rain crust can be found down 50 cm and exists up to around 2100 m. The bonds at the crust has shown variability though the region. It is important to dig down and test weak layers before dropping into your line. A large trigger such as a cornice fall or a skier/sledder hitting the sweet spot, could potentially trigger a large avalanche on this layer.
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.
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.