Snow conditions 14. 3. 2024

General danger level - Thursday, 14. 3. 2024
Danger is level 2 on the European five-level scale - MODERATE.
Main problem: drifted snow, wet snow
Danger pattern: Cooling after warm weather / warming after frost
Danger pattern: Spring situation

Risk assessment
Avalanche danger is MODERATE, level 2. The snowpack is mostly stable. Stability deteriorates during the day on all pronounced southern slopes, where a wet snow avalanche can be triggered. In high mountain gullies, the snow is still dry and drifted onto depth hoar layers in places - there is a risk of slab avalanche release with additional stress.

Snow conditions
With warm and sunny weather, the snowpack transforms rapidly - especially on southern slopes, where the snow surface has crusted up to the highest summits. On the most pronounced southern slopes below 2000 m, the top crust layer has frozen thick enough to support the weight of a skier and also a hiker. In forest cover and gullies, freezing was less intense, so the crust still breaks under a hiker's weight there. In shade, snow in the high mountains is still dry, but often compacted by wind action. On slopes up to 2000 m elevation, wet poorly bonded snow lurks under the crust. In the morning and forenoon, the snowpack on southern slopes below 2000 m is stable, as the hard crust bears the load of skier and hiker well enough to avoid overloading deeper layers. On southern slopes above 2000 m, the snowpack has not yet frozen thick enough, so there remains a risk of bonded snow slab release with overload of cornices especially near ridges. During the day, on the most pronounced southern slopes (first on SE slopes, then S and finally SW), the snow surface can soften to the point of becoming poorly bonded and unstable. Then and there, a wet snow avalanche can release spontaneously or with additional stress. Conditions in high mountain gullies are still wintery; with additional stress, due to weak layers present (depth hoar) in the snowpack, a slab avalanche can release on slopes that are not the steepest (below approx. 50°). Especially near ridges, snow is scoured to old frozen base in places, or to ice crust (refreeze), which formed up to 2200 m elevation from rain a week ago.

Forecast weather development
Friday and Saturday cloudy; on Friday high clouds will cover the sun, in the afternoon low clouds will build in the mid-mountains of S and W Julian Alps. Warm, zero isotherm around 2500 m, +4°C at 2000 m, +8°C at 1500 m. Saturday cloudy and foggy. Slightly cooler than Friday with zero isotherm at 2000 m. Light precipitation in mountains, a few cm of snow possible above 1800 m. Sunday morning clearing, after sunny forenoon clouding over again in the afternoon. Again warmer - similar to Friday. Atmosphere calm with little wind until Saturday evening; Saturday afternoon NW wind strengthening in high mountains, transitional weaker Sunday morning, moderate westerly by midday.

Trend in snow conditions
From Thursday afternoon, air in mountains more humid, also cloudy, so nocturnal surface freezing of snowpack especially below 2000 m less intense. There, on Friday, especially with rain on Saturday, a wet snow avalanche can release spontaneously. Snow transformation due to higher temperatures also more intense on northern slopes, poorly bonded dry snow (graupel) will gradually bond. New snow on Saturday will not affect avalanche release danger, rain below snow line will slightly worsen snowpack stability.

Next issue: Sunday, 17. 3. 2024

Source: ARSO