Another warm night prevented an overnight recovery. Danger will rise quickly today as the sun hits the slopes. Temps will finally drop overnight and will help to form strong surface crusts. Plan to start and end your days early this weekend.
Weather Forecast
Today will be warm and sunny with freezing levels are expected to rise as high as 3600m, and alpine temps in the shade reaching 10'C. Overnight temps are expected to drop below freezing which will finally allow an overnight recovery and the beginning of a melt-freeze cycle. Sat and Sun should be mostly sunny with alpine temps reaching 4'C.
Snowpack Summary
At treeline and above a ~30cm storm slab overlies a crust. Below the crust the upper ~70cm of snow is warm, moist and weak. Sustained S'ly winds at ridgetop will have built deeper, more cohesive slabs on lee and cross-loaded slopes. At 1300m the surface crust that formed overnight is only 3cm thick with a very weak overnight recovery.
Avalanche Summary
Natural avalanches continue to occur daily with loose wet avalanches running to valley bottom. They have been occurring primarily from aspects where the start zones are in the sun. On Wed a skier triggered a size 2.5 on the headwall of Youngs Peak; a W aspect at ~2675m. The avalanche was 20-80cm deep and ran 150m. Luckily the skier was not buried.
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.
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.