Confidence
Fair - Due to variable snowpack conditions
Weather Forecast
Friday: Light snowfall during the day intensifying to moderate in the late afternoon / Moderate southwest winds / Freezing level at 800mSaturday: Light snowfall / Light southwest winds / Freezing level at 1000mSunday: Possible sunny breaks / Light northeast winds / Freezing level at 1300m
Avalanche Summary
Observations were limited on Wednesday; however, explosives control produced slab avalanches to size 2 which formed in response to strong winds and rapid loading. On Thursday a size 2 slab was ski cut on a northeast aspect (unknown elevation). The bed surface was the early April temperature crust.
Snowpack Summary
Moderate amounts of snow fell on Wednesday. In the south of the region, heavy accumulations (~40cm) were observed. At lower elevations rain continued to saturate the snowpack. The storm was accompanied by moderate to strong south/southwest winds which left variable snow distribution in exposed terrain with dense wind slabs forming in lee and cross-loaded features. Up to 85cm below the surface you will likely find a melt-freeze crust from last week's sunny weather. At the same interface, you may find spotty surface hoar on high north facing terrain. Large natural activity and remote triggers from earlier in the week suggest the surface hoar may continue to be reactive, especially with the weight of the new snow. Cornices are very large and could pop off with continued mild temperatures.
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.