Snow conditions 20.4.2023

General danger level - Thursday, 20.4.2023
Danger level is 3 on the European 5-level scale - CONSIDERABLE.
Main problem: wind slab, wet snow
Danger pattern: Spring situation

Risk assessment
Avalanche danger is in the high mountains above about 1800 m above sea level CONSIDERABLE (considerable), 3rd level, below about 1800 m, where old snow still persists, everywhere MODERATE, 2nd level. With increasingly warmer weather, spontaneous southern snow avalanches are occurring. Glide avalanches are possible on steep grassy slopes. In the higher high mountains, areas of wind slab still exist, now covered by new snow, making the danger hard to recognize. Even with minor loading, you can trigger an avalanche. With lower altitude, the release danger decreases rapidly. Greater attention is needed especially in gullies and below walls, where avalanches can reach lower.

Snow conditions
Overnight it was cloudy and foggy, with local precipitation occurring. The snow line was at altitudes from 1300 to 1800 m. In the mid-mountains only a few centimeters of snow fell, in the high mountains 5 to 20 cm. The freezing level temperature is currently at about 1700 m above sea level. Lower down, the snow has become heavily wet also due to rain, wet snow avalanches are occurring. Higher up it snowed with light to moderate winds from southerly directions. The wind transported fresh snow only on exposed spots. The snowpack in the high mountains is dry and crusty, snow depth is uneven. In the mid-mountains there are more and more bare patches.

Forecast weather development
Today cloudy and foggy. The lower edge of clouds will be at about 1000 m above sea level. Light to moderate local precipitation will occur, weakening in the afternoon. The snow line will vary. Above about 1400 m it will mostly snow. Light southerly to southeast wind will blow. Temperature at 1500 m around 3, at 2500 m around -3 °C. On Friday variable to mostly cloudy, summits occasionally in clouds. In the afternoon local showers, mainly snow, possibly thunder. Light southeast wind. Temperature at 1500 m around 4, at 2500 m around -3 °C. On Saturday partly clear, low clouds possible in mid-mountains in the morning and forenoon. During the day some variable cumulus clouds will form. Light westerly wind. Even warmer. The 0 °C isotherm will rise above 2500 m during the day. On Sunday variable to mostly cloudy and occasionally foggy. Late afternoon and evening light precipitation, partly showers, will start forming. Snow only in high mountains. Light to moderate westerly wind. Temperature at 1500 m around 6, at 2500 m around 0 °C.

Trend in snow conditions
Due to gradual thaw and more sunny weather, the avalanche release danger will not decrease significantly yet. Initially moderate release danger in high mountains, 2nd level, during the day it will increase and above about 1800 m become CONSIDERABLE (considerable), 3rd level, lower MODERATE, 2nd level. Main dangers will be wet snow avalanches and in high mountains also slab avalanches. Conditions will remain demanding, considerable caution needed when choosing a safe route.

Next issue: Friday, 21.4.2023

Source: ARSO