An overnight transition from rain to snow leaves us with some uncertainty for Wednesday. Expect the new snow to form touchy slabs in areas where it accumulates.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
Tuesday night: Rain and snow mixed with up to 10 cm of new snow accumulating in the alpine. Light to moderate southwest winds. Freezing level dropping from 2000 to 1200 metres.Wednesday: Cloudy with continuing flurries bringing about 5 cm of new snow. Light south winds. Freezing level to 1000 metres with alpine high temperatures of -3.Thursday: Mainly sunny. Light northeast winds. Freezing level rising to 1400 metres with alpine high temperatures of -2.Friday: A mix of sun and cloud. Light north winds. Freezing level rising to 1500 metres with alpine high temperatures around -1.
Avalanche Summary
No recent notable avalanches have been reported.
Snowpack Summary
After a period of light rain, new storm slabs are expected to form on the surface with up to 15 cm of new snow expected by Wednesday evening. The new snow will accumulate on a variable surface of wet snow and crust.Below the surface, the overall snowpack is well settled and strong. New cornices formed and old ones grew more overhanging with the snowfall at the end of last week. Cornices become more unstable as the temperature rises and as they are loaded by rain and new snow.
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.