Snow conditions 14.4.2023

General danger level - Friday, 14 April 2023
Danger is level 4 on the European five-level scale - HIGH.
Main problem: wind slab, new snow
Danger pattern: Cooling after warm weather / warming after cold

Risk assessment
Due to the large amount of newly fallen snow, the avalanche danger is currently HIGH, level 4, in the high mountains of the Julian Alps and western Karawanks, CONSIDERABLE (considerable), level 3, in the rest of the high mountains, and below about 1600 m, where there is still old snow, everywhere MODERATE, level 2. Steep slopes in the high mountains are especially dangerous, where spontaneous avalanches of poorly bonded snow are expected. At the same time, with the north wind especially in the high mountains, new wind slabs are forming. Areas of unstable snowpack are difficult to recognise. In the mid-mountains, more southern snow fell first, which has bonded somewhat better to the base.

Snow conditions
On Thursday and overnight into Friday, it snowed heavily in the mountains. The snow line was mostly between 800 and 1100 m above sea level. The snowpack increases rapidly with altitude. In the mid-mountains, a total of 30 to 60 cm of snow fell, in the high mountains 50 to 80 cm. During the snowfall, a light to moderate northeasterly wind initially blew, which only built snow deposits in exposed places. The snowfall is easing and has stopped in many places. However, the northerly wind is strengthening, moderate, and in places strong in the high mountains. The wind is transporting dry snow and building wind slabs, cornices and ridges on the southern sides of ridges and saddles. The new snow has bonded poorly to the base especially in the high mountains. Below about 1500 m above sea level, the snow has already softened somewhat and settled. The 0 °C isotherm is currently at about 1400 m above sea level.

Forecast weather development
In the afternoon, mostly cloudy weather is expected, with the sun occasionally breaking through the clouds, and the high mountain peaks in clouds. Occasional light to moderate precipitation, snow line at about 1200 m above sea level. Mostly moderate northerly wind. Temperature at 1500 m around -1, at 2500 m around -7 °C. On Saturday, cloudy and foggy. Occasional precipitation, snow line between 1100 and 1400 m above sea level. Light to moderate westerly winds, weakening during the day. Temperature at 1500 m around 0, at 2500 m around -6 °C. Overnight into Sunday, partial clearing in the western mountain groups. On Sunday during the day, cloudy and foggy again, light precipitation starting from the east. Snow line at about 1400 m above sea level. Northeasterly wind strengthening again. A degree or so warmer. On Monday, mostly dry with some showers, cloud cover breaking up. Moderate to strong northeasterly wind. Warming up during the day, temperature at 1500 m around 5, at 2500 m around -3 °C.

Trend in snow conditions
Snow and avalanche conditions will not improve significantly by the end of the week. An additional 5 to 20 cm of snow is forecast. Avalanche danger will thus be above about 1600 m CONSIDERABLE (considerable), level 3, and lower MODERATE, level 2. In the high mountains, fresh snow deposits will pose the main danger, where a wind slab avalanche can be triggered with minimal load. Spontaneous avalanches of new, poorly bonded snow are possible. Conditions will be difficult and dangerous, so we recommend avoiding the high mountains for at least a day or two. Great caution is also needed lower down. As soon as the sun shines, the danger on sun-exposed slopes will increase with the daily cycle. Currently, increased avalanche activity is expected especially on Monday, with more sun and warmer weather.

Next issue: Monday, 17 April 2023

Source: ARSO