Snow conditions 4. 1. 2024

General avalanche danger level - Thursday, 4. 1. 2024
Danger is level 2 on the European 5-level scale - MODERATE.
Main problem: wind slab, new snow
Danger pattern: Cold weather, fresh snow poorly bonded by wind

Risk assessment
Avalanche danger in the high mountains, above about 1800 m a.s.l., is MODERATE, level 3, elsewhere mostly LOW, level 1. Steep slopes in the high mountains are particularly dangerous, where new snow has not bonded well with the firm base, and additionally considerable wind slabs have formed due to the strong southwester. In the snowpack there are locally thin unstable layers of facets or surface hoar. In the mid-mountains there is less snow, it was also more wet and bonded better to the base, so the danger is much lower there.

Snow conditions
In the mountains, a few centimetres of snow fell overnight to Wednesday. In the mid-mountains it rained in places at sub-zero temperatures, probably forming a thin ice crust. Especially in the high mountains a moderate to strong southwester blew, which continued to transport snow and build new snow deposits, mainly found on eastern and northern slopes. Snow considerably reworked by wind, lots of wind slab, which may be unstable especially below ridges and passes. Today it has warmed up considerably. Snow has softened somewhat on sun-exposed aspects, more pronounced in the mid-mountains. Wind-scoured areas have iced up.

Forecast weather development
This afternoon sunny weather will continue, some cloudiness will remain mainly in the mid-mountain area of the Southern Julian Alps. In the high mountains moderate to strong northwester, in mid-mountains light to moderate westerlies. The 0 °C isotherm will be at around 2000 m a.s.l. Tomorrow, Friday morning, it will cloud over quickly, summits will enter fog. Local precipitation will start to appear by midday, spreading in the afternoon over all mountain ranges. Snow line at 1200 to 1600 m a.s.l., starting to rise in the evening. Moderate wind blowing, possibly strong southwester in high mountains. Temperature at 1500 m around 1, at 2500 m around -5 °C. On Saturday cloudy and foggy with abundant precipitation. Snow line in the morning at 1300 to 1800 m a.s.l., in the area of the eastern Julian Alps and western Karawanks possibly lower. In the afternoon the snow line will start descending from the north. Light to moderate wind of variable direction. Midday temperature at 1500 m around 1, at 2500 m around -3 °C. On Sunday cloudy and still quite foggy. Snowfall will weaken and cease in the western ranges. A strengthening northerly will blow. In total 40 to 60 cm of snow will fall in the high mountains, 20 to 40 cm in the mid-mountains.

Trend in snow conditions
By the end of the week, weather and avalanche conditions in the mountains will become very unfavourable and dangerous. Tomorrow, Friday, conditions will remain more or less unchanged. Due to abundant snowfall, the danger of avalanche release will DISTINCTLY INCREASE on Saturday, especially in the high mountains, where a weak layer is present in the snowpack or snow will fall onto a hard, icy base. On a larger scale, spontaneous sloughing of wind slab and poorly bonded snow is expected. On Sunday a strengthening northerly will blow, building new slabs on the southern sides of ridges and passes.

Next issue: Friday, 5. 1. 2024

Source: ARSO