Solar input and rising freezing levels may push the danger higher than forecast. Make conservative terrain choices and avoid slopes that might be affected by a cornice failure.
Confidence
Moderate - Timing or intensity of solar radiation is uncertain on Friday
Weather Forecast
The high pressure ridge remains firmly in place for the next 2 days. Mostly clear skies with the possibility of high cirrus in advance of the next Pacific frontal system scheduled to arrive in the area on Saturday. Although there is some disagreement in the forecast models, freezing levels are forecast to go above 1500 metres and some models are pushing the freezing level to 3000 metres. Winds are forecast to be light to moderate from the south-southwest.
Avalanche Summary
Cornice failures are highlighted from yesterday, triggering size 2.5 to size 3 avalanches. On the eastern slopes there were no reports of avalanches.
Snowpack Summary
Wind slabs have formed in lee terrain at treeline and above. A melt freeze crust which formed during the 2nd week of February has been recently reported between 20 and 45 cm, and may be more deeply buried in the south of the region. This crust layer has also been reported with surface hoar and facets in some places, and is definitely a layer to keep in mind. East of the divide wind slabs should be on your radar. Wind transported snow has also encouraged new cornice growth. These cornices are reported to be huge and unsupported. With warm weather and sun in the afternoon, these could become a significant hazard.
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.