Avoid exposing yourself to slopes that are getting affected by the springtime sun. The danger rating reflects conditions during the warm part of the day.
Confidence
Fair - Timing or intensity of solar radiation is uncertain on Sunday
Weather Forecast
Light snow fall is expected on Sunday, petering to flurries on Monday. On Tuesday, a ridge moves in, starting a few days of fine, sunny weather. The freezing level is around 1500 m by day, falling towards valley floor by night. Winds are generally light.
Avalanche Summary
A handful of recent large avalanches have been reported over the last few days. Many of these have been on north aspects, with the odd event on other aspects. There has also been a number of cornice falls.
Snowpack Summary
Recent squally snow showers have brought 10-25 cm of snow, which has been shifted into wind slabs. This new snow sits above a crust which varies in thickness with elevation. Cornices are large and should be given a respectful berth. Sun is likely to destabilize new snow and cornices.Two crust/facet interfaces, formed in March and February, sit about 80-120 cm deep in the snowpack. These weaknesses are becoming more stubborn to trigger, but still react in snowpack tests and have potential for wide propagations and very large avalanches if triggered. Most likely trigger spots would be thin snowpack areas, or triggering with a large load like a cornice fall.Basal facets are on operators' list of concerns. Deep snowpack issues sometimes wake up in the spring, so should not be forgotten.
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.