Snow conditions 9.12.2019

Danger is at level 2 on the European 5-level scale - MODERATE.

Main problem: new snow, wind-blown snow

Danger pattern: Cooling after warm weather / warming after cold

Danger pattern: Snowfall after prolonged cold period

Danger pattern: Cold weather, poorly bonded fresh snow with wind



Risk assessment

Avalanche danger is currently in the high mountains above about 1800 m MODERATE, level 2, lower down LOW, level 1. There are many windslabs and slabs that can release especially on steeper slopes under minor snowpack loading.



Snow conditions

In recent days, there has been sunny weather in the mountains with a strong temperature swing. The air was dry, so snow on sunny aspects softened somewhat during the day and froze at night, while in shady areas it remained dry. Yesterday, the westerly wind strengthened, but due to the mostly hard snow base, it did not transport additional snow. The snowpack is crusty on sun-exposed slopes, mostly soft in shady, sheltered areas. Where exposed to wind, it is also hard or crusty. There are many windslabs, wind-exposed areas are heavily scoured. Today it has cooled, minor precipitation has occurred, but the snowpack state has not changed significantly yet.



Forecast weather development

Today it will be cloudy and foggy. In the morning, minor precipitation will occur mainly in the west, which will intensify in the afternoon and spread to eastern mountains as well. The snow line will initially be between 1200 and 1500 m, only in the area of the eastern Julian Alps also below 1200 m. In the afternoon, the snow line will drop below 700 m. A moderate southwesterly wind will blow, weakening in the afternoon and turning southerly. An estimated 5 to 20 cm of snow will fall. At 1500 m around 0 °C, at 2500 m -5 °C. Tomorrow morning or midday it will clear up, then mostly clear weather will prevail. A strong northerly wind will blow. It will cool down. Temperature at 1500 m around -4 °C, at 2500 m around -8 °C. On Wednesday clear, wind will ease. In the afternoon it will warm slightly. On Thursday we expect clouding, occasional light snowfall, but precipitation amounts will be small.



Trend of snow conditions

It will snow in the mountains today. New snow will fall on a hard base; since dry snow will fall in the high mountains, it will bond poorly with the base. Moderate southwesterly wind will transport new snow and build slabs and windslabs. Tomorrow a strong northerly wind will blow, scouring snow to the old base on exposed spots. On south sides of ridges and passes, more extensive areas of wind-blown snow will form. Danger of slab avalanches will above about 1800 m INCREASE and be CONSIDERABLE, level 3, below 1800 m it will remain level 1 due to smaller snow amounts. On Wednesday, with transient warming, the snowpack will stabilize only slowly.



Next issue: Thursday, 12. 12. 2019



Source: ARSO