Snow conditions 31.12.2021

General danger level - Friday, 31. 12. 2021
Danger is level 2 on the European five-level scale - MODERATE.
Main problem: wind-blown snow, wet snow
Danger pattern: Cooling after warm weather / warming after frost

Risk assessment
Avalanche danger is mostly MODERATE, level 2, due to pronounced warming. Steep sun-exposed grassy slopes are particularly dangerous, where spontaneous wet snow avalanches and gliding avalanches will be possible during the day at all altitudes. Individual crusts may also collapse. In the high mountains, areas with wind-blown snow remain dangerous, where slab avalanches can be triggered under high stress. Greater danger is primarily in shady gullies, where there is a larger amount of wind-blown snow. Particularly in shady aspects, there is also considerable gliding risk.

Snow conditions
Over the last two days, mostly clear and warm weather with occasional cloudiness prevailed in the mountains. In the high mountains, a few centimetres of snow fell overnight to Thursday with the passage of a warm front. A moderate, occasionally strengthening north-westerly wind blew, creating new snow deposits to a lesser extent. The old snowpack base is hard or crusted, softer bases are almost gone even in shady sheltered areas. On wind-exposed aspects, snow is scoured to the ground in places. The snowpack softened significantly yesterday, especially on sun-exposed aspects, and melted, freezing slightly overnight due to clearing skies. This process will be even more pronounced today and in the coming days. The hardness of the snowpack will largely depend on the aspect. With very high temperatures for this time - near record values - the snowpack will become unstable especially on sun-exposed aspects. Snowpack melting will be significantly slower due to the drier air mass than would otherwise be expected at such high temperatures.

Forecast weather development
Today it will be clear. The wind will be light. Only over the high mountain tops will a moderate north-wester blow. The air will be dry and very warm. The zero isotherm will be at around 3500 m elevation! At 1500 m it will be around 11, at 2500 m around 7 °C midday. On Saturday it will be mostly clear, with increasing high cirrus cloudiness in the afternoon. A light to moderate north-wester will blow, temporarily strong in the high mountains in the morning. A degree or so less warm. At 1500 m around 10, at 2500 m around 5 °C. Sunday too will be mostly clear, with increasing mid and high cloudiness towards evening. A light to moderate south-wester will blow, strengthening in the afternoon. Still warm. At 1500 m around 8, at 2500 m around 5 °C. At the beginning of next week, low cloudiness from over Primorska will spread into central Slovenia. Clearer initially still in the high mountains and northern ranges. Gradually cooler.

Trend in snow conditions
The snowpack will also soften, settle and melt at the end of the week due to warming, especially on sun-exposed aspects. Particularly during the day, the danger of wet snow avalanches and gliding avalanches will increase. Steeper grassy slopes will be particularly dangerous. Particularly in shady gullies, there will still be danger of slab avalanches. Avalanche release danger will thus remain MODERATE, level 2. Bare patches will increase on southern slopes. The next avalanche bulletin will be published on Monday, 3.1.2022.

Next issue: Monday, 3. 1. 2022

Source: ARSO