Confidence
Fair - Intensity of incoming weather is uncertain
Weather Forecast
Synopsis: A weak frontal system moves through the region on Saturday and is replaced by a ridge of high pressure.Saturday: 5-10 cm new snow. Ridgetop winds 40 km/h from the west, gusting to 60 km/h. Freezing level 2100 m.Sunday: Light snow, 2-5 cm. Possibly higher accumulations in the east. Light northwesterly winds. Freezing level 500 m.Monday: Dry. Light winds. Freezing level at valley bottom with treeline temperatures around -5C.
Avalanche Summary
A skier accidentally triggered a windslab on Wednesday. This avalanche had a crown from 30-60 cm thick.
Snowpack Summary
Warm temperatures have moistened the snow surface in many areas. As temperatures cool, expect it to harden into a crust. Wind slabs are extensive in exposed areas and cornices are reported to be well developed. A surface hoar/facet/sun crust layer from mid February (12th) may be buried in the top 20 cm or so, where it hasn't been blown away by the wind and is likely making some of the wind slabs more touchy. Mid and lower snowpack layers are generally well settled and stable.
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.