Snow conditions 13.12.2019

Danger is level 3 on the European five-level scale - CONSIDERABLE.

Main problem: new snow, wind-packed snow

Danger pattern: Snowfall after a prolonged cold period

Danger pattern: Cooling after warm weather / warming after cold



Risk assessment

Avalanche danger is currently in the high mountains above about 1800 m MODERATE, level 2, lower down LOW, level 1, but will INCREASE during the day due to snowfall. There are many wind slabs and loose snow, which can mainly trigger on steeper slopes mostly only under significant additional load on the snowpack.



Snow conditions

On Thursday, 5 to 15 cm of dry snow fell in the mountains, the least in the eastern part of our mountains, the most in the Julian Alps. The new snow is light and heavily wind-drifted. The base is mostly crusty or hard, only in sheltered high mountain locations soft. Today during the day snow conditions will CHANGE RAPIDLY!



Forecast weather development

Today it will be cloudy and foggy, precipitation will intensify in the west and gradually spread over the Kamnik-Savinja Alps and eastern Karawanks, where snow will start only late afternoon or evening. A strong southwesterly wind will blow, turning to northerly to northeasterly in the evening. Tomorrow mostly clear. A light to moderate westerly wind will blow. Zero isotherm around 2000 m. On Sunday in the eastern part of our mountains initially partly clear, more clouds in the afternoon. Elsewhere moderately to mostly cloudy and also foggy. In the western and southern Julian Alps and foothills occasional light precipitation. Snow line around 1600 m. Strengthened southwesterly wind. On Monday weather similar, also quite cloudy in the east. Snow line around 2000 m.



Tendency of snow conditions

The snowpack will start to thicken today during the day. By tomorrow morning 20 to about 40 cm of snow will fall in the Julian Alps. Similar amount expected on Snežnik, 10 to 30 cm elsewhere in our mountains. It will snow mostly on a hard base, so there will be a weak layer under the new snow along which the new snow can slide. Wind will form wind slabs. In the coming days it will warm up considerably at altitude. Initially due to warming the snowpack will become more unstable. We expect spontaneous releases first of loose new snow avalanches, then also slab avalanches, lower down also ground avalanches on steep grassy slopes. At the same time the snow will settle and transform faster and by Monday or Tuesday the snowpack will somewhat stabilize.



Next issue: Monday, 16.12.2019



Source: ARSO