Confidence
Fair - Forecast snowfall amounts are uncertain on Thursday
Weather Forecast
The ridge of high pressure is expected to bring clear skies and colder temperatures to the region on Wednesday. The temperature in the alpine should be about -15.0 and the winds should increase to about 40 km/hr from the west-northwest by Wednesday evening. Cloud and light precipitation should move into the region from the Pacific during the day on Thursday. This system is expected to bring 5-10 cm of snow to higher elevations. Thin cloud and increasing upper elevation winds are expected for Friday.
Avalanche Summary
Several small skier controlled avalanches in 35 degree terrain failing down about 20 cm.
Snowpack Summary
Very strong southwest winds have transported the storm snow into windslabs in the alpine and at treeline. There is a new rain crust below 1500 metres and an old rain crust that is buried down about a metre below the 1600 metre elevation. The mid-pack is reported to be strong, and I have not heard anyone talk about early season layers deep in the snowpack. That being said, there is still a lot of variation due to the strong winds that have accompanied most storms this winter in the region. I would continue to be suspect of thin snowpack areas.
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.