Tune in to solar radiation and daytime warming and their effect on snow stability.
Weather Forecast
A mix of sun and cloud today with no precipitation forecast. Alpine temperatures should reach a high of -4C with light SW winds. The freezing level should rise to 1600m. A cool, unstable air mass is the name of the game for the next few days.
Snowpack Summary
High elevation N'ly aspects above 2400m remain wintery, with winter stability issues. Warm temps and solar radiation have resulted in moist surface snow with the upper snowpack being a series of crust layers. Below treeline expect the snowpack to be isothermal. We are moving slowly into a spring melt freeze cycle.
Avalanche Summary
Several natural avalanches in the hwy corridor observed yesterday with the largest being a size 3 slide on Avalanche crest. Skiers have recently triggered soft slabs on high elevation N aspects. Sunday skiers triggered a size 2 slab on Cheops N5 at 2250m, it was 20cm deep and ran 300m. Shooting cracks caused a group to turn around on Ursus Major.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.
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.