Solar radiation and day time heating will rapidly and dramatically increase the avalanche danger. Pay close attention to the effects of sun on the snowpack as the afternoon approaches. Start your trip early and finish early if its a warm afternoon.
Weather Forecast
Cool air from the north will remain over the area on Tuesday with the possibility of up to 5cm of fresh show. The greatest snowfall is forecast to occur to the east and at upper elevations. Moderate ridge top winds from the N and NW will redistribute the snow onto southerly and easterly facing slopes. Temps at treeline will approach zero in mid PM.
Snowpack Summary
A spring temperature crust up to 15cm thick can be found near the top of the snowpack. This crust has been found as high as 2600m in the Icefields area. In places it is buried under several inches of new snow. Wind slabs can be found at upper elevations on most aspects due to varied wind direction patterns. Cornices are large and dropping.
Avalanche Summary
No new avalanches were reported today. One avalanche was reported late Friday above the icefalls on the Athabasca glacier which originated from steep, cross loaded gullies in the high alpine. Cooler temperatures and no solar radiation due to cloud cover has reduced natural activity in the last few days.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Tuesday
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.
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.