Snow conditions 22. 3. 2024

General danger level - Friday, 22 March 2024
Danger is level 2 on the European five-level scale - MODERATE.
Main problem: wet snow
Danger pattern: Cooling after warm weather / warming after cold
Danger pattern: Slopes covered with graupel

Risk assessment
Avalanche danger is MODERATE, level 2, the snowpack is mostly stable. Stability deteriorates during the day in sunny weather on all pronounced sun-exposed slopes, where wet snow avalanches may be triggered. In the high mountains, snow can be hard and icy especially in wind-exposed areas, posing a risk of slipping.

Snow conditions
Under the influence of warm weather, the snowpack has started to transform faster even in the high mountains, while in the mid-mountains snow is melting mainly on sun-exposed aspects. Sun-exposed slopes are bare in many places up to 1800 m a.s.l., in shady areas the snowpack starts around 1300 m. Snow conditions in the mountains are quite spring-like. These days, snow softens during the day and refreezes at night even in the high mountains. Yesterday, Thursday afternoon and evening, some light snow fell in local showers above 2000 m, which does not affect snowpack stability. Below 2000 m, rain wet the snowpack, and a crust with a smoother surface formed during the clear night. Today it is slightly cooler and drier than yesterday, but sunnier. Wet snow avalanches can still release spontaneously, especially on pronounced sun-exposed slopes.

Forecast weather development
Today sunny, patchy clouds will form in the afternoon, summits may be in clouds. Weak to moderate northerly winds will blow. Temperature at 1500 m is 7 °C, at 2000 m 2 °C, at 2500 m around 0 °C. Saturday will initially be mostly sunny and warmer than today, zero isotherm overnight and in the morning near 3000 m. Southwesterly winds will strengthen in the morning and blow all day. Cloudiness will increase in the afternoon, a cold front will pass in the evening. Cold air will flow in the lowest atmospheric layers from the north/northeast, while in the mountains a strengthened southwesterly will still blow. In the area where the air masses meet, first in the north of the country, then increasingly towards the south, convective precipitation, showers and thunderstorms will form, which the wind will carry northeast. The area and duration of these precipitations is impossible to predict precisely, but we expect that in some precipitation bands more than 40 liters of precipitation per square meter could fall in a few hours. Due to the convective nature, locally a large part of the precipitation may fall as graupel or soft hail, elsewhere snow will prevail. The snow line will depend on the influx of cold air at the ground and precipitation intensity, so large differences over short distances are expected. Above 2000 m, hard precipitation (snow, soft hail, graupel) will fall continuously. For a short time during heavy precipitation, it may snow below 500 m a.s.l. Sunday morning will clear from the northwest, some showers possible in the afternoon. Slightly cooler.

Trend in snow conditions
Overnight to Saturday, snow below about 2000 m will refreeze less pronouncedly and will soften quickly in the sunny morning. This will increase the likelihood of spontaneous wet snow avalanches, especially on pronounced sun-exposed slopes. At the start of precipitation Saturday evening and even more with the influx of colder air, the old snowpack will refreeze, but new precipitation will not bond well with it. During precipitation, strengthened southwesterlies will blow, fresh wind slabs will form. Where graupel balls or hail appear during precipitation, small new snow avalanches may release spontaneously during the precipitation. Winds will calm only Sunday morning; until then, some new wind slabs will form, which will be the main avalanche problem on Sunday. Where more than 20 cm of snow falls below 2000 m, wet snow avalanches will release spontaneously on steep slopes during Sunday's daytime melt.

Next issue: Monday, 25 March 2024

Source: ARSO