The snowfall of the past few days has created a tense avalanche situation. At the end of the week, a warm front will bring very mild temperatures and rain up to high altitudes. At the weekend, the signs in the Eastern Alps are pointing to a northern thaw.
Current situation and outlook
We are still in a westerly flow, with the Alpine region located between a high over south-western Europe and a low over Scandinavia and the Baltic States. Embedded in this low, various fronts will move towards the Alps over the next few days. On Thursday (23.2.), a first warm front will make it significantly warmer. Thanks to an advance of warm air, Friday will bring temperatures that we wouldn't actually expect for another two to three months. Winter will return on Sunday, possibly even with a fair amount of fresh snow in the north-east.
Snow cover
We'll leave the snow of the future to our colleague Orakel. The snow of the past is at least as important, so let's take a look back with the help of a current profile from the Brenner region (see graphic). More than half of the two-metre-thick snow cover consists of a homogeneous layer of old snow, which we owe to the snowfall during Andrea and Co. There is very little floating snow on the ground (at this point the ground consists of alpine rose bushes). The upper, recently formed layers are more relevant for skiers. At 140 cm, a thin crust of melted snow can be seen, which is undergoing a build-up transformation. The temperature data from the nearby station on the Tuxer Joch suggests that this crust formed on February 8 during a brief cold spell.
The legacy of the cold
Above this is a layer of angular crystals about 20 cm thick. This formed during the long cold period in the first half of February and can be found in many regions of the Northern Alps. Due to the low temperatures, the layer, which was still superficial at the time, was largely transformed. The station data shows that it snowed on February 16th with strong winds. The resulting layer of wind-pressed snow lies on top of the loose, angular layer. On February 20, it snowed again (before that, surface frost had formed, thin layer at 170 cm), this time with little wind influence. The top layer is therefore loose, nice to ski, glistens very temptingly in the sun and hides the drift snow pacts above the unfavorable, angular layer from the cold period.
The WeatherBlog is taking a break from the internet for the next two weeks and will hopefully be back with March powder and imperial weather.
