Another 15 to 20cm of snow will add to the already 40cm+ of storm snow. The recent snowfall, winds and warm temps have led to widespread storm slab and cornice development. Avalanche activity will continue Sunday. It's time for conservative choices!
Confidence
Fair - Forecast snowfall amounts are uncertain
Weather Forecast
5 to 10cm of snow (rain at lower elevations) is possible overnight Saturday with temperatures slowly dropping. Sunday could bring another 10cm under cooler conditions. winds will be moderate and variable, swapping form the NW to the NE. The storm should end by midnight on Sunday.
Avalanche Summary
Several cornice triggered and naturally triggered slabs were observed today up to size 2.0. These occurred mostly on SE and NE aspects mostly in alpine start zones. Most of the slides observed had significant run-outs. Loose wet avalanches at lower altitudes were also observed today on all aspects up to size 1.5.
Snowpack Summary
20 to 25cm of heavy, dense snow fell overnight with storm snow totals now near 40cm at treeline. Widespread storm slab development in alpine and treeline areas. Cornices are growing and several cornice collapses were observed today. Moist snow exists below 1900m due to light rain through the day.
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.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.