Snow conditions 31.12.2023

General avalanche danger level - Sunday, 31 December 2023
The danger level is 2 on the European five-level scale - MODERATE.
Main problem: wind-blown snow, new snow
Danger pattern: Snowfall after a longer period of frost
Danger pattern: Wind slab covered with snow

Risk assessment
The avalanche danger is LOW, level 1, but increasing due to snowfall. The old snowpack is mostly well bonded and stable, dangerous only on individual steep slopes and gullies in the high mountains where there is more wind-blown snow. The snowpack surface is frozen mainly in gullies and on wind-exposed locations. On this base, 20-50 cm of snow will fall in the next 24 hours. Weather conditions will be unfavourable for outdoor New Year's Eve celebrations in the mountains due to poor visibility, wind, precipitation and new snow.

Snow conditions
Sunny and unseasonably warm weather continued. Snow settled, became wet during the day and froze at night, the surface crust mostly supports weight. There is very little snow in the mid-mountains, some slopes are bare up to 2000 m.

Forecast weather development
Light snow is already falling in the west above 1300 m, accompanied by moderate southwesterly wind. In the next hours, the southwesterly wind will strengthen further, it will warm up, the snow line will rise at least above 1500 m, only above 1800 m mostly dry snow will fall. Precipitation will intensify in the afternoon and spread to the east in the evening. The main amount will fall by Monday morning, with possible heavier precipitation with graupel in between. In the second half of the night, it will cool down, the snow line will drop below 1000 m in the north. On Monday morning, a strong northerly wind will blow temporarily, but it will calm down during the day and be replaced by a weak westerly. On Monday morning, partial clearing from the west will occur in the northern half of the country, but high cloudiness will appear by midday.

Trend in snow conditions
On the hard base, more than 50 cm of dry snow will fall in the Western and Southern Julian Alps above 1800 m, up to 20 cm of wet snow above 1500 m. Elsewhere, up to 30 cm of dry snow above 1800 m. During snowfall, wind will build drifts on the northern side of ridges, after wind shift smaller drifts may form on the southern side as well. Poor bonding of new drifts to the old base will be the greatest threat in the coming days. The risk of loose slab avalanche release will be even higher where graupel also falls.

Next issue: Monday, 1 January 2024

Source: ARSO