Snow conditions 18. 4. 2025

General danger level - Friday, 18. 4. 2025
Danger is 3rd degree on the European 5-level scale - CONSIDERABLE.
Main problem: wet snow, gliding snow
Danger pattern: Rain

Risk assessment
Avalanche danger below around 2000 m is CONSIDERABLE, 3rd degree. The snowpack is mostly wet and in many places saturated to the ground. Rain has reduced cohesion of the upper layers of the snowpack even in the high mountains, and in some places has caused saturation of the entire snowpack with water. Therefore, the snowpack is less stable. Avalanches of wet cohesive and non-cohesive snow can release spontaneously or with minimal loading. Ground avalanches and slab collapses are also possible. Above 2000 m, due to cooling, the snowpack is temporarily somewhat more stable, so the general danger there is MODERATE, 2nd degree.

Snow conditions
In recent days it has been warm and rainy in the mountains, with at least occasional rain up to the highest peaks. Today the snow line has dropped to around 1600 m above sea level, zero isotherm at around 1800 m. Small to medium-sized loose wet snow avalanches have released, and in places also ground avalanches. The snowpack is wet on the surface, below 2000 m wet all the way to the ground. Higher up, on old snow there is up to around 10 cm of fresh snow. Below around 1800 m, quite a lot of snow has melted.

Forecast weather development
Today, Friday, it will be cloudy and foggy in places, precipitation will gradually cease. Snow line at around 1600 m. Weak to moderate southwesterly wind. On Saturday in the mid-mountains on the Primorska side of the Dinaric-Alpine barrier it will be cloudy and also foggy, with occasional light rain in places. Clouds will also linger on ridges elsewhere. Some sun in the eastern part of our mountains. Zero isotherm will rise above 2500 m during the day. Moderate southwesterly wind, which will strengthen somewhat in the afternoon. On Sunday it will be mostly sunny, with clouds lingering mainly on the ridges of the western and southern Julian Alps and the foothills, elsewhere less than on Saturday. Strong southwesterly wind. Zero isotherm above 3000 m above sea level. Also on Monday mostly sunny with considerable cumulus cloudiness, possible afternoon shower.

Tendency of snow conditions
The snowpack is wet, saturated to the ground in many places. Due to the slightly cooler air mass, gliding will be less likely today, Friday, than in previous days, but still possible especially below around 2000 m elevation. Ground avalanches and slab collapses will also be possible. On Saturday, however, due to the renewed rise in temperature, the probability of avalanche release will increase only slightly, while on Sunday and Monday, due to sunnier weather, the possibility of gliding from mid-morning onwards will be greater. Otherwise, the snow will slowly settle and melt and stabilize in the long term. Even the new local precipitation forecast for next week will not significantly increase avalanche danger; only in the high mountains, above around 2200 m, where there is still quite a lot of snow, warm weather will somewhat increase the possibility of spontaneous release from steep slopes.

Next issue: Monday, 21. 4. 2025

Source: ARSO