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.
Weather Forecast
Saturday/Sunday: The high pressure system digs deeper! Winds remain light under clear, sunny skies. Alpine temperatures climb to 6 degrees for Sunday afternoon with freezing levels reaching 3000m. It is possible that there will not be a refreeze at treeline and below on Sunday night.Monday: The ridge should begin to break down. Skies will remain clear, light southwesterly winds should begin to blow and alpine temperatures will reach just above freezing.
Avalanche Summary
Loose wet avalanches up to 2.0 have been reported on solar aspects. One size 3.0 wet slab released on the surface hoar crust combo (suspected) from steep terrain (40 degrees) on a south aspect in the low alpine in the last 48hrs.
Snowpack Summary
Recent warm temperatures have created melt freeze crusts up to 2000m on all aspects and to ridgecrest in the alpine on south and west facing terrain. These crusts break down with daytime warming and the surface snow can lose cohesion as a result. Isothermal conditions as deep as 100cm have been reported on South aspects at lower elevations. Cornices are huge!Various melt-freeze crusts are buried in the upper snowpack. In general, the bond at these interfaces is good. A layer of surface hoar (buried on March 11; now down about 60 cm) is still being observed in some locations. Triggering this layer has become less likely, but possible with a large trigger or from a thin snowpack zone. Mid and lower snowpack layers are well bonded.
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.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.