Snow amounts will vary highly throughout the region, with 15-30 cm. Storm slabs will build throughout the day and strong southwest wind will form fresh wind slabs. Choose conservative terrain if you see more than 15 cm new snow and wind is moving snow.
Springtime cornices are large and unpredictable. New snow and wind will further grow cornices, and the additional load can lead to cornice failures. Give them a wide berth when travelling at ridge crest and avoid overhead exposure.
Storm slabs will build throughout the day. The amount of new snow will be highly variable in the region and can range from 15 to 30 cm by the end of the day on Monday.
Strong southwest wind will redistribute the new snow and build fresh wind slabs in lee terrain features in the alpine and at treeline.
The slabs will be most reactive to human triggers where they overlie a crust.
Sunday night: Cloudy, 10-15 cm snow, strong southwest wind, alpine low -4 °C, freezing level at 1500 m.
Monday: Cloudy, 10-15 cm snow, moderate to strong southwest wind, alpine high -4 °C, freezing level at 1500 m.
Tuesday: Cloudy, 10-15 cm snow, moderate to strong westerly wind, alpine high -5 °C, freezing level at 1500 m.
Wednesday: Sunny, trace of new snow, light to moderate west wind, alpine high -4 °C, freezing level at 1600 m.
On Saturday, a large wind slab avalanche (size 3) released naturally on a northern aspect in the alpine. Many small slab and dry loose avalanches released naturally and were triggered by skiers. They were 10-30 cm deep and ran on the recent crust.
On Friday, small natural dry loose avalanches were observed. A skier triggered cornice resulted in a size 2 avalanche. Skiers triggered a few small wind slab, storm slab and wet loose avalanches.
On Thursday, numerous small size 1 wind slabs, dry loose, and wet loose avalanche activity were observed.
The snow surface became moist on sun-exposed slopes up to 2000 m in the last couple of days and formed a crust overnight.
The new snow will add to 10-40 cm recent snow that overlies a crust from late March. The amount of snow on the crust tapers rapidly at lower elevations. This crust is present on all aspects up to an elevation of 2500 m. Below the crust, the snow is moist.
The upper snowpack consists of multiple crusts that were formed in March and February.
The early-December rain crust is approximately a metre off the ground. Reports have recently indicated that large slab avalanches have failed on this interface earlier last week following a rain and warming event. This layer may be dormant now due to colder weather, however, it may appear again during the next big warm-up or with increased load from wind, snow and/or rain.
