Snow conditions 15.12.2022

General avalanche danger level - Thursday, 15 December 2022
The danger level is 2 on the European five-level scale - MODERATE.
Main problem: wind slab, new snow, wet snow
Danger pattern: Cooling after warm weather / warming after cold
Danger pattern: Cold weather, fresh snow poorly bonded by wind

Risk assessment
Avalanche danger above sea level around 1800 m is MODERATE, level 2, lower down LOW, level 1. Slabs are particularly dangerous, mostly on western and southern sides of ridges and saddles. There, even with a small load on the snowpack, you can trigger an avalanche. Wind-blown areas are icy in places. Lower down, due to the small amount of snow and intermediate thaws and coolings, the snowpack is more stable. In the coming days, avalanche conditions in the mountains will WORSEN!

Snow conditions
Snow in the high mountains is mostly dry and soft, but crusted in places due to wind influence. Due to thawing, snow in the mid-mountains is becoming more wet, higher up the air humidity is still too low. There are many drifts and patches, wind-blown spots are icy in places.

Forecast weather development
Weather is changing rapidly. Today it will cloud over in the high mountains as well. Towards evening, precipitation will start in the west and spread quickly eastwards in the evening. The snow line will rise, in the Alps area mostly around 1700 m above sea level, but initially much lower in some closed valleys. Further south, it will rain up to around 1900 or even 2000 m above sea level. Tomorrow, Friday, precipitation will temporarily weaken and especially in the northeast also stop. During the day it will become more frequent again, but appearing more in bands from southwest to southeast. More of it in western and southwestern Slovenia. On the night to Saturday it will cool down, the snow line will drop to the lowlands in many places in the interior of Slovenia in the second part of the night. Precipitation will stop everywhere by noon. It will cool markedly, north winds will blow. On Saturday morning temperature at 1500 m around -5, at 2500 m around -9 °C. From Sunday onwards a few days of dry weather. Already on Sunday warmer air will flow into the heights and by Sunday evening or Monday morning it will warm up to zero at 1500 m, but the air will be dry. The temperature gradient will strengthen.

Trend of snow conditions
On the night to Friday and during Friday, below the snow line the snowpack will get wet, so wet snow avalanches may release from steep slopes, especially ground avalanches on grassy slopes. In the high mountains, 10 to about 40 cm of snow is expected, most in the Julian Alps, least in the eastern Karawanks. The southwesterly will transport snow into drifts. The possibility of spontaneous release of new snow from steep slopes will increase, numerous new slabs will form. On Pohorje it will mostly rain. On the night to Saturday and then until Saturday morning it will snow rapidly lower. The amount of precipitation will be somewhat less than on Friday. In the high mountains it will snow onto a soft and loose base, lower onto wet, so the snow there will bond better. 10 to 30 cm of snow will fall, mainly depending on altitude, somewhat less again in the eastern part of the mountains. North to northeasterly wind will create new drifts. In areas at sea level altitudes where it will rain on Friday, the new snow will not significantly worsen avalanche conditions, as there will be too little of it and the bond between the base and new snow will be relatively good. Higher up, the new snow will somewhat increase the release potential, areas of wind slab will form also on southern and western slopes. On Sunday cold weather, so avalanche conditions will not change much.

Next issue: Friday, 16 December 2022

Source: ARSO