Forecast snowfall amounts are uncertain on Tuesday. HIGH danger is possible if you see more than 30 cm of fresh snow on the ground before the end of the day.
Confidence
Moderate - Forecast snowfall amounts are uncertain on Tuesday
Weather Forecast
TUESDAY: Periods of snow – up to 30 cm. The freezing level is around 800-1000 m. Ridge winds are moderate from the south. WEDNESDAY: Possible sunny breaks to start with snow developing late in the day. The freezing level could rise to 1200-1400 m. Ridge winds are light but increase to strong from the SW-SE with the arrival of the storm. THURSDAY: Cloudy with sunny breaks and a chance of flurries. The freezing level is near 1400 m and winds are light.
Avalanche Summary
Natural avalanche activity up to size 2 was reported on Sunday, primarily from freshly wind loaded slopes. Skier testing also produced several slabs up to size 1.5 on steep and unsupported slopes. On Saturday there was evidence of widespread natural storm slab avalanche activity to size 3.5. The avalanches failed in response to heavy storm loading on Friday and possibly warming on Saturday.
Snowpack Summary
Storm totals from the past week were well over 100cm with more currently falling and much more on the way. Previous strong southwesterly winds have shifted the new snow into deeper storm slabs on lee and cross-loaded alpine and treeline features. On all but higher elevation shaded slopes, the new snow from Sunday likely overlies a melt-freeze crust from high freezing levels and sun on Saturday afternoon. Ongoing stormy weather has also encouraged extensive cornice growth. Weaknesses below the recent storm snow are expected to have gained considerable strength while the mid and lower snowpack are also 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.