Wind slabs remain sensitive to human triggering in steep terrain. Solar radiation will be a significant factor over the next few days. Pay attention to increasing danger levels as daytime heating and radiation affect solar aspects and cornices.
Confidence
Good - Timing or intensity of solar radiation is uncertain
Weather Forecast
Mostly sunny for the next several days with generally light winds. Temperatures will be seasonal and no precipitation is expected.
Avalanche Summary
A few naturally triggered slab and loose avalanches occurred today. A few small cornice failures also occurred. One significant slide, size 2.0, was observed midday on an East aspect at 2700m. This slide initiated as a small sluff, which then triggered several small slabs on the moderate angled rock bands below. Debris was channeled into a gully feature.
Snowpack Summary
The snowpack continues to settle. Moist snow on steep solar aspects in the afternoon. Wind slabs remain prominent in Alpine and open Treeline terrain, especially on N and E aspects. These slabs are sensitive to human triggering in steep, convex or un-supported terrain. Cornices are large in some areas and regular failures have been occurring over the past several days. Buried crust layers are a concern on solar aspects when radiation is high and/or temperatures are warm.
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.
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.
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.