Variable snowfall amounts are expected across the region. Danger ratings are set for areas with strong winds and 20-30 cm snow overnight.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain on Wednesday
Weather Forecast
Tuesday night/ Wednesday: Strong SW wind. Alpine temperature near -8. 20-30 cm snow.Thursday: Light N wind. Alpine temperature near -12. No precipitation.Friday: Light W wind. Alpine temperature near -16. No precipitation.
Avalanche Summary
A couple of small (size 1-1.5) storm slabs were observed on Monday. The size and frequency of avalanches is likely to increase with storm snow and wind loading.
Snowpack Summary
New snow is developing into slabs, with a weak bond to old snow surfaces including surface hoar (at and below treeline) and facets. By Wednesday morning, storm snow totals could be 80-90 cm 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.