Snow conditions 28.12.2020

Danger is 4th level on the European five-level scale - HIGH.

Main problem: drifted snow, new snow, weak layers



Risk assessment

Avalanche danger is currently above about 1700 m CONSIDERABLE, 3rd level, lower down MODERATE, 2nd level, but it will significantly increase during the day. New snow that fell a few days ago was heavily drifted by strong northerly wind and formed numerous wind slabs and crusts. On some slopes, you can trigger a slab avalanche already with minor loading. Overnight, moderate to strong southerly wind started blowing, already building new slabs. At the same time, snowing started. Conditions will start to change rapidly in the next hours. Due to abundant new snow, we expect spontaneous dry snow avalanches. Upon contact with hard and icy base, the snow will bond poorly, and at the same time the new snow cover will overload the drifted snow, so spontaneous slab avalanches will also be possible. Also due to bad weather, we advise against visiting the mountains.



Snow conditions

In the high mountains, there is a thick snowpack that strong wind has heavily reshaped. Wind-exposed spots are heavily scoured and icy in places, on leeward slopes there are numerous slabs that have also crept. Due to cold weather, the snowpack has transformed and stabilized only slowly. Moderate to strong wind has today started building new snow deposits mainly on northern and north-western slopes. More favourable conditions are in the mid-mountains, where the snowpack is also significantly thinner. Below the tree line, there is also some light snow. The snow cover reaches all the way to alpine valleys. Until morning, about 5 cm of dry snow fell. Today and tomorrow we expect heavy snowfall, especially in the high mountains a strong wind from southerly directions will blow. The state of the snowpack will change rapidly.



Forecast weather development

Today it will be cloudy and foggy with snow showers. By evening, a total of 20 to 70 cm of snow may fall, the most in the Julian Alps area, less in the eastern mountain ranges. Strong wind from southerly directions will blow. Temperature at 1500 m around -2, at 2500 m -7 °C. On Tuesday, in the eastern Karawanks and on Pohorje variable to mostly cloudy, and occasionally foggy in places, elsewhere mostly cloudy and foggy. Occasional snowing, more frequently in the western half of our mountains. We expect an additional 10 to 40 cm of snow to fall. Moderate to strong southwesterly wind will blow. Temperature at 1500 m around -2, at 2500 m -8 °C. On Wednesday morning or forenoon snowing will stop, during the day clouds will break. Southwesterly wind will weaken. At 1500 m around -3, at 2500 m around -9 °C.



Trend in snow conditions

Avalanche release danger will this afternoon and tomorrow due to the large amount of new snow above around 1500 m HIGH, 4th level, lower down MODERATE 3rd level. New snow will bond poorly with the base in many places, and at the same time due to overloading of the old snowpack, slab avalanches will also release spontaneously, new slabs will form on northern and north-western slopes. Particularly dangerous will be steep slopes, gullies and steeper grassy slopes, where full-depth avalanches will also be possible. New snow will cover old slabs, so the danger will be difficult to recognize. Due to cold weather, the snowpack will transform and stabilize only slowly. We advise against visiting the mountains in the coming days.



Next bulletin: Wednesday, 30. 12. 2020



Source: ARSO