Snow conditions 19.5.2021

The danger is 3rd degree on the European five-level scale - CONSIDERABLE.
Main problem: wet snow, new snow
Danger pattern: Spring situation

Risk assessment
Avalanche danger in the high mountains of the Julian Alps above about 2100 m above sea level is CONSIDERABLE, 3rd degree, elsewhere where there is still sufficient snow MODERATE, 2nd degree. Above about 2100 m above sea level there is new snow that may slide off steep slopes. Today and tomorrow we expect individual spontaneous avalanches, and an avalanche can also be triggered by minor loading of the snowpack. Numerous wind slabs have formed in the high mountains. Lower down, rain has soaked the old snowpack, which has therefore become less stable, and a wet snow avalanche may release from steep slopes there. In the mid-mountains, snow is melting and receding.

Snow conditions
It started snowing overnight, the snow line dropped to about 1300 m above sea level. The zero isotherm is in the morning at about 1500 m above sea level. Snow is dry and poorly bonded to the substrate in the high mountains, lower down wet. New snow in the high mountains 20 to 40 cm, lower down up to about 10 cm, but it will mainly snow in the morning. Strong northerly wind is forming wind slabs. Below the snow line, old snow is soaked, otherwise well transformed and settled.

Forecast weather development
Today cloudy and foggy. In the morning mostly snowing in the mountains, in the afternoon snowfall will gradually cease. Cloud base will rise, but larger clearings very unlikely until evening. Strengthened northerly winds blowing. Tomorrow fairly sunny and somewhat warmer, zero isotherm rising to about 2200 m above sea level. Moderate northerly wind blowing, weakening in the afternoon. Friday partly clear with occasional increased cumulus cloudiness, some cloudiness over peaks especially in Posočje. Moderate southwesterly wind. Slightly warmer. Saturday in western and southern Julian Alps already mostly cloudy and foggy along ridges, occasionally light rain in places, above about 2000 m light snow. Elsewhere less cloudy and dry.

Trend in snow conditions
In the mid-mountains, the snowpack will continue to recede, snow will not refreeze due to high humidity and considerable cloudiness on the night to Thursday. In the high mountains, new snow will settle, but initially will slide off steep slopes, especially Thursday on sun-exposed slopes when the sun will soften it during the day. Avalanches can be triggered even on wind-packed snow areas with minor snowpack loading. Dangerous will be steep and tomorrow sun-exposed slopes above about 2100 m above sea level or even higher. Lower down the snowpack is mostly settled and transformed and, despite saturation, fairly stable. Even in the high mountains, avalanche danger will decrease rapidly after Thursday.

Next issue: Friday, 21.5.2021

Source: ARSO