Snow conditions 12.12.2022

General danger level - Monday, 12 December 2022
Danger is level 2 on the European five-level scale - MODERATE.
Main problem: wind slab
Danger pattern: cooling after warm weather / thaw after frost
Danger pattern: snowfall after prolonged frost period

Risk assessment
Avalanche danger is above about 1800 m altitude MODERATE, level 2, lower down LOW, level 1. Wind slabs are particularly dangerous, mostly on western and southern sides of ridges and passes. There even with minor additional load on the snow cover you can trigger a snow avalanche. On scoured spots it is icy in places. Lower down due to small snow amounts and intermediate thaws and coolings the snowpack is more stable.

Snow conditions
Snow conditions in the mountains are quite varied, depending on both altitude and geographical location. Below about 1800 m there has been rain several times in the past followed by snow, hence much less snow there than above this altitude. There the snow has continuously settled and hardened, freezing upon cooling. On Sunday 5 to 15 cm of loose snow fell on this hard base. Higher up mostly snowed in the past, so snowpack is much less transformed with weak layers inside. Lots of drifts, cornices on ridges. On more wind-exposed sites snow is crusty or hard, in lee areas accumulated loose snow from Sunday snowfall. Of course more snow in the Julian Alps and western and central Karawanks. In places wind has scoured snow to the icy base.

Forecast weather development
Today, Monday, mostly clear, weak to moderate northwesterly in high mountains. Tomorrow morning mostly clear, afternoon cloudiness spreading from the south, which is hard to precisely predict if it will reach our alpine region. It may cloud over in the afternoon with summits in clouds, or the edge of cloudiness may stay a bit further south veiling only the low winter sun. Less likely clouding in eastern Karawanks and Pohorje. Weak to moderate southerly to southwesterly in high mountains. In the afternoon somewhat warmer air arriving at height. Wednesday morning mostly cloudy and locally foggy, afternoon clearing more in the eastern part of our mountains, while in the west cloudiness gathering below about 1700 m altitude. Southwesterly somewhat strengthening. Warmer air continuing to arrive and by evening especially in high mountains it may warm above zero. Thursday partly sunny in eastern part of our mountains, further west mostly cloudy and locally foggy. Towards evening precipitation starting in western part of Julian Alps and hills of Notranjska and northern Primorska, strengthening overnight to Friday covering all of Slovenia. Friday morning tapering off. Strong southwesterly. Snowfall limit rising to between 1600 and 1800 m altitude.

Trend in snow conditions
Until Wednesday noon no major changes in avalanche and snow conditions. In cold spots surface hoar and possibly depth hoar forming in areas with thin snow cover. Wednesday afternoon snow starting to settle and transform somewhat due to warming, Thursday this process more pronounced. Due to warming wind slabs becoming somewhat more potentially unstable, possibly some spontaneous avalanches triggered, especially in the evening in the west where rain will further worsen conditions lower down, higher new snow. By Friday morning danger expected to increase above about 1800 m to level 3, lower to 2. Individual full-depth wet snow slab avalanches possible from steep grassy slopes.

Next bulletin: Thursday, 15 December 2022

Source: ARSO