As this past week's storm snow continues to settle it will still be important to evaluate the bond between the old snow surface and the new snow. There is still potential for a week sliding layer in sheltered areas.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
Thursday: Isolated flurries, accumulation trace / Moderate south wind / Alpine temperature -8Friday: Flurries, accumulation 5cm/ Light east wind / Alpine temperature -7Saturday: Cloudy with isolated flurries/ Light north wind / Alpine temperature -9
Avalanche Summary
On Monday, numerous natural slab avalanches were reported up to size 2.5 from a variety of aspects and elevations. On Tuesday a few explosives triggered and natural avalanches were reported from northerly aspects in the alpine. Natural avalanche activity may taper Thursday, however; skier triggered avalanches are still possible.
Snowpack Summary
Up to 60 cm of storm snow sits above a variety of old snow surfaces including wind affected snow, faceted (sugary) crystals, surface hoar crystals and a thin sun crust on steep solar aspects. There is a bit of uncertainty regarding how the new snow is bonding to these old snow surfaces. Two potential weak layers deeper in the snowpack may become reactive under the new load from the recent storm snow. The first being a spotty surface hoar layer down 40-80 cm and then the mid-November crust that sits 100-200 cm down. Recent test results on these layers have varied from moderate and sudden to hard and resistant, and in some cases no result.
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.