New wind slabs are one reason to tread carefully on Thursday, the extensive recent avalanche cycle is another. Avoid rushing into (or under) large terrain until the snowpack has stabilized.
10-25 cm of new snow may accumulate in the alpine by end of day Thursday with moderate to strong south winds. Expect touchy new wind slabs to form wherever this new snow accumulates instead of rain.
Buried weak layers are particularly concerning where recent rain has soaked the upper snowpack, reaching down to old crusts. Predicting these avalanches is especially challenging, and triggering them may have serious consequences.
The upper snowpack has been soaked and weakened by rain. This problem will end once a substantial surface crust forms. Until then, wet loose avalanches remain possible in steep terrain.
A widespread avalanche cycle took place in the region through the early week, with numerous wet slab and wet loose avalanches to size 4 (very large) seen in a wide range of terrain. One report from Tuesday featured a size 4 with a crown fracture over 3 km long!
Looking ahead, light new snow should generate surface instabilities as cooling temperatures reduce the odds of deep avalanches. Given the scale of recent activity, there's no rush to jump back into large terrain.
Alpine elevations ought to collect 10-25 cm of new snow on a surface crust by end of day Thursday. Otherwise, light rain will keep the upper snowpack at treeline and below largely saturated with water.
The mid and lower snowpack consists of variable layers of crusts and faceted snow.
Overall the snowpack remains unusually shallow and continues to melt at lower elevations.
Wednesday night
Cloudy with light rain or wet snow, possible 5-10 cm accumulating in the hight alpine. South alpine winds 20 to 40 km/h, freezing level around 2000 m.
Thursday
Cloudy with 5-15 cm of new snow in the alpine, rain below 1700 m. South alpine winds 10 to 20 km/h. Treeline temperature 0°C with freezing level around 1800 m.
Friday
Mostly cloudy with scattered flurries bringing less than 5 cm of new snow. Southwest alpine winds 10 to 20 km/h. Treeline temperature 0°C with freezing level around 1700 m.
Saturday
A mix of sun and cloud with isolated flurries. Alpine winds shifting northeast, 5-10 km/h. Treeline temperature -2°C with freezing level around 1400 m.
More details can be found in the Mountain Weather Forecast.
