Strong sunshine will increase avalanche danger during the day. Plan your route to minimize exposure to big sun-drenched slopes in the afternoon.
Weather Forecast
THURSDAY: Mainly sunny. The freezing level is around 1400-1600 m. Ridge winds are moderate from the northeast. FRIDAY: Mainly sunny. The freezing level should jump to around 1800-2000 m and ridge winds are light gusting to moderate from the southeast. SATURDAY: Increasing cloud. The freezing level is around 1800 m and winds remain light.
Avalanche Summary
Cornices continue to pop off with regularity. Some are triggering slabs below and others are not. In the north of the region on Sunday, a cornice collapse triggered a size 3.5 deep slab avalanche which failed on glacier ice. A second size 3.5 deep persistent slab was observed nearby on Tuesday likely occurring around the same time). Forecasts sunshine and warming will cause cornice activity to increase and result in loose wet sluffing from steep sun exposed slopes.
Snowpack Summary
Up to 75cm of snow fell over the last week or so. This snow is reported to be settling and gaining strength, but lingering storm instabilities may still exist, especially in recently wind loaded terrain features. Cornices are reported to be large and fragile. Expect to encounter a sun crust or moist snow on sun-exposed slopes depending on the time of day. The mid and lower snowpack are generally strong and well-settled. Below 1200m the snowpack is reported to be isothermal.
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.
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.
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.