Forecast new snow is not expected to elevate the danger on Wednesday. If there is more than 10 cm in your area, consider the danger to be a bit higher.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Wednesday
Weather Forecast
Snow developing overnight with moderate southwest winds and freezing levels around 1000 metres. Expect 5-10 cm by Wednesday morning and another 5-10 cm during the day. Light westerly winds and a few cm of snow or flurries on Thursday. The next major storm is forecast on Friday, expect strong southwest winds and 20-35 cm of snow above 1500 metres.
Avalanche Summary
Some reports from Monday of skier controlled soft slab avalanches up to size 1.5 where the surface snow has slabbed up above a less dense (one finger over fist) layer of recent storm snow. However, explosives control on Sunday produced several soft storm slab avalanches on a variety of aspects and elevations. Most of the activity was in the size 1 range, although a few results to a size 2 were also noted. A few size 2 cornice collapses were also triggered with explosives in alpine terrain. Looking forward, relatively calm weather should allow for strengthening and settlement in the snowpack, and avalanche activity should taper-off. I'd still remain cautious of human-triggered storm slabs, especially in steeper, high elevation terrain.
Snowpack Summary
Snow depths increased rapidly last week bringing treeline snow depths to about 200 cm. Much of this recent storm snow has settled and gained significant strength. That said, the last burst of wind and snow on Saturday and Sunday created reactive soft storm slabs which appeared to be especially touchy in higher, wind-exposed terrain. Stormy weather also encouraged significant cornice growth, and new cornices are reported to be unseasonably large and fragile. Over a metre below the surface you'll find the thick mid-November crust. The reports we've received suggest a reasonable bond at this interface; however, I'd remain suspicious of this layer until the snowpack adjusts to the weight of all of the new snow. This may take a few more days. Below the crust, the snowpack is strong and well-settled.
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.
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.