Snow conditions 13.11.2017

General danger level - Monday, 13 November 2017

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

Main problem: new snow, wind drifted snow

Danger pattern: Cold weather, poorly bonded fresh snow with wind



Risk assessment

Avalanche danger has above sea level around 1700 m mainly increased in the Julian Alps due to new snow and is CONSIDERABLE, 3rd degree. Elsewhere above around 1000 m altitude MODERATE, 2nd degree, lower LOW, 1st degree. Since it snowed onto a crusty base, there is a weak layer in the snowpack along which a snow avalanche can slide. Where it snowed onto grassy base, on steep slopes snow can also slab off. Particularly dangerous are steep slopes with old snow cover, and grassy slopes and places with wind drifted snow. There even with minor snowpack loading a snow avalanche can be triggered locally. In the high mountains of the Julian Alps spontaneous sloughing of smaller avalanches from steep slopes is expected, a ground slab avalanche also possible on steep grassy mid-mountain slopes.



Snow conditions

In the Julian Alps and western Karawanks 10 to around 30 cm of snow has fallen, in the Kamnik-Savinja Alps and eastern Karawanks 20 to 40 cm, also in hills of the rest of Slovenia currently new snow 10 to 20 cm, in Zasavje also over 30 cm. In the high mountains it snowed onto crusty base, lower mostly onto bare ground. Snow is currently light and soft and dry in the hills. At the beginning of snowfall moderate to strong southwesterly blew, with the passage of the cold front strengthened winds from northern directions started blowing, transporting snow into wind slabs on south and west sides of ridges and saddles. Ridges are quite wind scoured. The snowpack reaches the lowlands.



Forecast weather development

On Monday cloudy, snowfall will cease everywhere by evening. Another 5 to around 10 cm snow can fall. Strong northeasterly to northerly wind will blow, weakening on Tuesday, still blowing also on Wednesday. Zero isotherm until Wednesday at around 900 m above sea level, on Wednesday rising to 1200 to 1400 m. Transient partial clearings on the northwest already in the night to Tuesday, elsewhere Tuesday afternoon and night to Wednesday, then clouding up again.



Tendency of snow conditions

The snowpack will due to cold and mostly cloudy weather settle and transform only slowly. Wind will continue transporting snow into wind slabs on west and south sides of ridges and saddles. Avalanche danger will decrease slowly, snow will stabilise somewhat better on Wednesday with slightly warmer air mass especially in the mid-mountains.



Next bulletin: Wednesday, 15 November 2017



Source: ARSO