Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain on Saturday
Weather Forecast
Thursday: Mostly clear skies / Light/northwest winds / -12.0 @ 1500mFriday: Mostly clear skies in the morning with increasing cloud in the afternoon and trace amounts of snow / Light southwest winds / -8.0 @ 1500mSaturday: Light to moderate snowfall / Moderate southwest winds / Freezing level rising to 850m
Avalanche Summary
A few size 1.5-2 windslab avalanches occurring in the alpine. Some failing with cornice fall.
Snowpack Summary
2 days ago very strong southwest winds 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.