2.02.2023
General avalanche danger level - Thursday, 2. 2. 2023
The danger is level 3 on the European five-level scale - CONSIDERABLE.
Main problem: wind slab, loose snow, wet snow
Danger pattern: Cooling after warm weather / warming after cold
Risk assessment
Avalanche danger above sea level around 1600 m is CONSIDERABLE (or significant), level 3, lower down and in some pre-alpine areas (northern Primorska, Polhograjsko and Škofjeloško hribovje, Posavsko hribovje and similar) MODERATE, level 2. Steeper slopes above the forest line are dangerous, where there are extensive areas of wind slab present on numerous aspects. There you can trigger a slab avalanche even under small load. In the old snowpack, now hidden under a thick blanket of new snow, weak layers are present especially on shady slopes, which can give way at individual spots under additional load. This can happen especially where there is less snow due to wind influence. Below sea level around 1600 m, steep grassy slopes are mainly dangerous, where today due to warming we expect mainly wet snow avalanches and slab avalanches on sun-exposed slopes. Snow and avalanche conditions in the high mountains are very demanding.
Snow conditions
In the mountains it has warmed up a bit more. The zero isotherm is at sea level around 1500 m. Snow froze overnight, but during the day it melted on sun-exposed locations in mid-mountains and lower hills. Snow in high mountains and shady locations in mid-mountains is still poorly transformed. In sheltered shady locations, powder snow still persists in places. On the surface of the snowpack, crust is present in many places, formed by wind or daytime thaw and nighttime freezing. In mid-mountains moderate wind blows, in high mountains strong northwesterly wind, which on exposed locations transports smaller amounts of snow and builds new snow deposits on eastern and southern aspects. Especially above the forest line there are many places with wind slab, ridges are scoured to hard base. There are many slabs and cornices. The snowpack has stabilized overnight especially in mid-mountains, but during the day due to sun and higher temperature, wet snow avalanches can release mainly on steep grassy slopes.
Forecast weather development
This afternoon cloudiness will increase especially in mountain groups in the north, but the cloud base will mostly be above summits. Occasionally light snow flurries possible, more precipitation on Pohorje and eastern Karawanks. Strengthened northwesterlies will blow, strong especially in high mountains. Temperature at 1500 m around 0, at 2500 m around -7 °C. On Friday initially moderately to mostly cloudy, clearing during the day, more clear skies in western Julian Alps. Moderate to strong northwesterlies will blow, strengthening further in the evening. Temperature at 1500 m around 1, at 2500 m around -3 °C. Overnight to Saturday transitional light snowing again. On Saturday partly clearing, some variable cloudiness during the day. Strong northerlies will blow, weakening only slightly in the afternoon. Colder. Midday temperature at 1500 m from -1 to -6, at 2500 m around -8 °C, colder in mountain groups in the east. On Sunday initially partly clear in high mountains, clouding over during the day also there. In mid-mountains cloudy and also foggy weather will prevail all day. Especially in high mountains still very windy. Strong northerly wind will blow. Slightly colder.
Tendency of snow conditions
Today and overnight to Saturday total around 5 cm snow will fall in mountain groups in the north, on Pohorje and eastern Karawanks up to 10 cm. New snow will not increase avalanche danger. On Friday similar conditions as today expected. From Saturday onwards the snowpack will stabilize especially in mid-mountains. In high mountains snow and avalanche conditions will remain similar. On exposed locations strong northerlies will still transport snow. Icy surfaces will increase, therefore slipperiness danger will be greater.
Next issue: Friday, 3. 2. 2023
Source: ARSO