Confidence
Fair - Intensity of incoming weather is uncertain on Wednesday
Weather Forecast
Tuesday night/Wednesday: Strong SW wind. Alpine temperature near -9. 30-50 cm snow.Thursday: Light NW wind. Alpine temperature near -15. Light snow.Friday: Light NW wind. Alpine temperature near -16. No precipitation.
Avalanche Summary
Numerous size 1-2 storm snow avalanches were triggered naturally and by skiers on Monday. Explosives triggered storm snow avalanches to size 2.5. In some areas, activity was limited to loose dry sluffing or small very soft slabs. The size and likelihood of avalanches is expected to increase on Wednesday.
Snowpack Summary
New snow has been sluffing readily and developing into slabs, which have a weak bond to old snow surfaces including surface hoar, facets and a sun crust. By Wednesday morning, storm snow totals could be 1m or more in some areas, leading to the potential for deep and destructive storm snow avalanches. In wind-affected areas, wind slabs have formed behind terrain breaks such as ridges and ribs. A strong mid-pack overlies a weak facet/crust layer near the base of the snowpack.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.