Solar radiation is expected to be strong on Friday. Be alert on solar aspects as the recent snow will likely start to slide on solar aspects.
Weather Forecast
Friday: Expect a mix of sun and cloud with alpine temperatures of +1c. Winds are to be light from the North and a freezing level of 2000m. Solar radiation will be strong when the sun is out and will most probably affect southern slopes to mountain top.Saturday: Expect a mix of sun and cloud, alpine temperatures of +2c and a freezing level of 2200m. Solar radiation will be strong when the sun is out.
Avalanche Summary
Numerous sluffs within the new storm snow were observed on solar aspects but the cloud cover kept the solar radiation to a minimum. Friday is to be sunnier, so more activity is expected.
Snowpack Summary
This recent storm has dropped around 10-20cm of snow, more toward the East. Expect to find some soft slabs in the alpine. Expect this new snow to slide and entrain all of the storm snow, especially on solar aspects. . This new snow has fallen on top of a previous melt freeze crust that developed during last weeks heat wave. The main concerns at this time is the new snow sliding on solar aspects that are overlying the previous melt freeze crust as well as concerns associated with the deep persistent weak base. The freezing level on Thursday climbed to 2300m with some moist snow being found below this elevation. Untracked areas at treeline and below are weak isothermal. In these Spring conditions, the avalanche danger rating can deteriorate rapidly, especially with solar input.
Problems
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.