Snow conditions 15.12.2017

General danger level - Friday, 15.12.2017

The danger is level 3 on the European 5-level scale - CONSIDERABLE.

Main problem: fresh snow, wind-drifted snow

Danger pattern: cooling after warm weather / warming after cold



Risk assessment

The avalanche danger is currently above about 1300 m MODERATE, level 2, lower down LOW, level 1. Due to snowfall, it will increase above about 1300 m elevation to CONSIDERABLE, level 3 by night. Steep slopes and areas with wind-drifted snow in the high mountains are dangerous, where individual avalanches of new, dry snow can be triggered. An avalanche can be triggered with even minor loading of the snowpack on steeper slopes and in areas with wind-drifted snow. Lower down, the snowpack is mostly stable due to the smaller amount of snow.



Snow conditions

In the past 48 hours, 10 to over 20 cm of snow has fallen in the mountains above about 1300 m, which fell on a mostly soft base and bonded well with it. The snowpack there is mostly soft and loose, with some crust formed by wind. Strong southwesterly winds have blown much of the new snow away, exposing old snow or ground on wind-exposed spots. Overall, the stormy wind in recent days has created huge scouring. Lower down, there was light snowfall on Wednesday during the day with up to 10 cm of snow, and rain on Thursday, so the new snow settled and melted. There, on a harder, crusted base, there is some new snow.



Forecast weather development

Today, Friday, it will be cloudy with occasional precipitation, partly isolated showers. Towards evening, they will intensify and occur throughout Slovenia. The snow line will mostly be at around 1200 to 1300 m elevation in the morning, but will lower in the afternoon, and snow will fall to the lowlands overnight into Saturday. Strong southwesterly winds will blow, weakening in the afternoon and turning northeasterly in the evening. Tomorrow morning, snowfall will stop everywhere. Weak to moderate northerly winds will blow. In the afternoon, it will gradually clear from the northwest. On Sunday, partly clear with occasional increased cloudiness, short-term snow showers not excluded. Moderate winds, occasionally strong in the high mountains from the north. On Monday, dry and cold weather will continue. Winds will ease somewhat and turn westerly in the mid-mountains during the day. Temperatures will remain below zero from Saturday to Monday.



Trend in snow conditions

This afternoon and overnight into Saturday, avalanche danger will slightly increase above about 1300 m elevation due to new snow. Initially, southwesterly winds will form drifts, then northerly to northeasterly winds in the evening and overnight. Snow is falling on a soft and loose base, so thicker slabs may become avalanche-prone. The snowpack will be soft and loose. In the coming days, due to low temperatures, it will settle and transform only slowly, while northerly winds will continue to transport snow and form new drifts. Therefore, areas with wind-drifted snow will be particularly dangerous. Ridges and passes will be quite scoured.



Next issue: Monday, 18.12.2017



Source: ARSO