Snow conditions 17. 3. 2025

General danger level - Monday, 17. 3. 2025
Danger is level 4 on the European five-level scale - HIGH.
Main problem: weak layers, wind slab, new snow, wet snow
Danger pattern: Cooling after warm weather / warming after cold

Risk assessment
Avalanche danger is HIGH above 1800 m in the area of the western and southern Julian Alps, level 4, elsewhere CONSIDERABLE, level 3. Below 1800 m the danger is MODERATE, level 2. Since the beginning of last week, a huge amount of new snow has fallen in the high mountains. Moderate to strong south to southwest wind has transported snow in large quantities and created new areas of wind slab. In the high mountains, spontaneous release of even larger avalanches of new poorly bonded snow is still possible. In the mid-mountains, there is less new snow, as it partly rained and partly snowed. Conditions are unfavourable and demanding.

Snow conditions
Since Friday, 50 to 100 cm of new snow has fallen in the high mountains, the most in the area of the western and southern Julian Alps. The snow line has varied, mostly moving between 1400 m and 1800 m. During heavier precipitation, it may have snowed down to the bottom of the alpine valleys. Below about 1800 m, wetter snow fell, which therefore bonded better to the base. Moderate to strong south to southwest wind has transported snow in the past days and built slabs, ridges and drifts. In the high mountains, weak layers are still present in the old snowpack, especially on northern aspects, deep under the new snow.

Forecast weather development
Today, on Monday, it will initially be cloudy and foggy with light snowfall. In the afternoon, cloudiness will be somewhat more variable, some sunshine possible especially in the western Karawanks and western Julian Alps. Snow showers will form. In the high mountains, it will cool significantly towards evening. Weak to moderate northerly wind will blow, strengthening somewhat in the afternoon. At midday, temperature at 1500 m will be around -2 °C, at 2500 m around -9 °C. On Tuesday, initially mostly clear and cold, during the day shallow lenticular cloudiness will form, some peaks may occasionally be in clouds. In the morning moderate northeast wind will blow, weakening during the day. In the afternoon warmer air will begin to arrive. At midday, temperature at 1500 m still around -6 °C, at 2500 m around -10 °C. On Wednesday and Thursday mostly clear, temperatures will gradually rise.

Trend in snow conditions
Snow and avalanche conditions remain demanding, the main problems are new and wind slab snow. On Monday and Tuesday, the snow will transform little, remaining light and dry in the high mountains. Moderate northerly wind will redistribute snow to a lesser extent than in previous days. From Wednesday onwards, on sun-exposed aspects in clear and warmer weather, the snow will begin to transform faster. In the morning the snowpack surface will soften, at night it will refreeze, a crust will form on the surface. During the day, avalanche danger will increase on sun-exposed aspects.

Next issue: Thursday, 20. 3. 2025

Source: ARSO