If the skies are clear, expect the avalanche danger to increase in the afternoon. Serac fall may result from the warming temperatures on higher alpine climbing routes. Pay attention to overhead hazards and start your trip early in the day.
Weather Forecast
The skies will remain mostly clear and occasional high clouds in the afternoon through to the weekend. Some light sporadic snow flurries may come on the weekend with only trace accumulations. Temperatures will have high diurnal changes with strong solar radiation in the afternoons with freezing levels reaching 2000 meters.
Snowpack Summary
A variable thick slab exists in alpine and treeline locations on a variety of aspects. It is over a strong midpack except in shallow locations where you could trigger basal facets near the ground. A suncrust with varying thickness and strength exists at all elevations on steep South facing aspects. Below treeline, the crust breaks down by midday.
Avalanche Summary
Numerous loose snow avalanches were observed on steep South through West aspects at all elevations in the Icefields areas. They originate from steep rock bands and gully features where the sun heats the rocks. Below treeline, where the snowpack is thin, isothermal conditions are developing.
Confidence
Timing or intensity of solar radiation is uncertain on Friday
Problems
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
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.