Snow conditions 17.12.2021

General danger level - Friday, 17 December 2021
The danger is 2nd degree on the European five-level scale - MODERATE.
Main problem: wind-blown snow, wet snow
Danger pattern: Cooling after warm weather / warming after frost

Risk assessment
The avalanche danger is mainly above the treeline MODERATE, 2nd degree, lower down mostly LOW, 1st degree. Particularly dangerous spots with freshly wind-blown snow, especially on south-facing slopes above the treeline. This applies especially to gullies, where there is a larger amount of wind-blown snow. In shady high mountain locations there are also weak layers in the old snowpack that can fail especially where there is less snow. Due to warmer daytime weather, we expect individual small wet snow avalanches and gliding avalanches to release especially on sun-exposed steep grassy slopes. Many places are icy, so the risk of slipping is considerable.

Snow conditions
The snowpack has been subject to melting and freezing in recent days, especially on sun-facing aspects. Below the treeline, the snowpack is relatively well bonded and transformed, with crust forming in many places. There is relatively little dry and unbonded snow. Conditions are different in the high mountains above 2000 m, where the transformation process of the snowpack has been significantly slower. On exposed aspects, a moderate northerly wind has been blowing continuously, strongly reshaping the snowpack surface. Numerous slopes are wind-scoured to hard and in places even to bare ground. The wind has deposited snow mainly on south slopes, where there are numerous snowdrifts, slabs and cornices. In shady and sheltered high mountain locations, weak layers in the old snowpack may have formed due to clear weather. On sun-facing aspects during the day, due to warm weather, we expect the snow to become quite wet, so individual wet snow avalanches and gliding avalanches are possible. This applies especially to steep grassy slopes.

Forecast weather development
Today it will be mostly clear, especially in the eastern part of the Karawanks and on the Pohorje in the afternoon occasionally more cloudy. A moderate, in high mountains also strong northerly wind will blow. Temperature at 1500 m will be around 2, at 2500 around -2 °C. A few degrees warmer on the Julian Alps area. Overnight we will have a transient cooling, a strong northerly wind will blow. Tomorrow mostly clear, some clouds in the eastern part of our mountains in the mid-afternoon or evening. A moderate to strong northerly wind will blow, weakening during the day. Temperature at 1500 m from -5 to -1, at 2500 around -5 °C. On Sunday clear, with moderate northerly winds a very warm air mass for this time will reach us. At 1500 m from 4 to 8, at 2500 m around 0 °C. Also at the beginning of next week dry and windy weather will continue. It will cool significantly. On Monday afternoon at 1500 m around -4, at 2500 m -10 °C.

Trend in snow conditions
Also in the following days up to Monday, the cycle of snowpack melting and freezing will continue. The crust will strengthen, icy surfaces will increase. On exposed parts of the high mountains, strong northerly wind will transport snow and continue building new slabs. On Sunday we expect pronounced warming, so during the day especially on sun-facing slopes the danger of wet snow avalanches and ground avalanches will INCREASE. Above the treeline CONSIDERABLE, 3rd degree, lower down MODERATE 2nd degree. Especially steep grassy slopes will be dangerous. Some slabs on south slopes may also fail. Due to cooling, the snowpack will stabilize quickly on Monday. But there will be considerable slipping risk. The next avalanche bulletin will be published on Monday, 20.12.2021.

Next issue: Monday, 20 December 2021

Source: ARSO