Snow conditions 29.12.2021

General avalanche danger level - Wednesday, 29. 12. 2021
Danger is level 2 on the European five-level scale - MODERATE.
Main problem: wind slab, wet snow
Danger pattern: Cooling after warm weather / warming after cold

Risk assessment
Avalanche danger is above about 1800 m elevation and on sun-exposed aspects MODERATE, level 2, elsewhere LOW, level 1. More dangerous are places with fresh wind-blown snow above the treeline, where small slab avalanches can be triggered already with minor additional stress. With large additional stress, it is also possible to trigger medium-sized avalanches of older wind slab. This applies especially to gullies, where there is a larger amount of wind-blown snow. In shady high-alpine aspects there are also weak layers in the old snow cover that can fail especially where there is less snow. With pronounced daytime warming, steeper sun-exposed slopes in the mid-mountains will also become more dangerous, where spontaneous wet snow avalanches and glide avalanches are possible. This especially applies to steeper grassy slopes. In the high mountains and shady aspects there is considerable glide danger.

Snow conditions
Overnight with the passage of the front it snowed briefly for a short time, on exposed aspects a strengthened northwester blew temporarily. Up to 5 cm of snow fell, more precipitation was in the area of the Kamnik-Savinja Alps and in the eastern Karawanks, where up to 10 cm of snow fell in the high mountains. Snow fell on a hard and crusty base, but due to the modest amounts avalanche danger did not increase. Except where new snow is blown into slabs. The old snow base is hard or crusty, softer bases are almost no longer present even in shady sheltered aspects. On wind-exposed aspects snow is scoured to bare ground in places, and there is also glide danger because of this. Especially in lower and sun-exposed aspects the snow cover thins slightly during the day and refreezes at night. This process will be even more pronounced in the coming days.

Forecast weather development
Today mostly clear with some cirrus clouds. More cloudy occasionally especially on Pohorje. Weak to moderate northwester will blow, more pronounced in the high mountains. Temperature at 1500 m from 2 to 5 °C, at 2500 m around -4 °C. Warmer in the western ranges. Overnight a weakened front will pass from the northwest again. Especially in the high mountains a few centimeters of snow can fall. After the front passage a strengthened northwester will blow in the morning, which will weaken during the day but will still be weak to moderate. During the day partly clear with occasional moderate cloudiness. Even warmer! At 1500 m midday around 7, at 2500 m around 0 °C. On Friday clear. Wind weak. Only on the summits of the high mountains moderate northwester. Air dry and very warm. Zero isotherm will rise to about 3400 m elevation. At 1500 m midday around 12, at 2500 m around 6 °C. Also at the end of the week mostly clear and warm. Air temperature only one degree lower.

Tendency of snow conditions
Due to warming the snow cover will soften especially on sun-exposed aspects, lower also in shady gullies, settle and also melt. Especially during the day the danger of wet snow avalanches and glide avalanches will increase. Especially steeper grassy slopes will be dangerous. The snow cover transformation process will be much slower due to the drier air mass than would otherwise be expected at such high temperatures. Especially in shady gullies there will still be danger of slab avalanches. The danger of triggering avalanches will remain MODERATE, level 2. Due to melting and freezing of the snow cover, icy surfaces will increase. The next avalanche bulletin will be published on Friday, 31.12.2021.

Next publication: Friday, 31. 12. 2021

Source: ARSO