The change in the general weather situation suspected last week is a thing of the past, the western slide is doing well and low pressure system Fabienne is on the horizon. After a few fantastic winter days with freezing cold postcard weather, the next batch of powder is just in time for the weekend.
Current situation and outlook
Today, Wednesday (18.1.2012), large parts of the Alps were still under the influence of a high pressure system over south-western Europe, which was already severely affected in the east yesterday and will finally have to leave the field tomorrow. Low pressure system Fabienne will first send us a warm front, which will cause a risk of black ice at lower altitudes as the ground is cold after the last few days and rain from the front will freeze on it. The snow line rises to well over 1000 m. The cold front will follow on Friday and with it a return to the kind of temperatures you want in January, at least if your toes aren't freezing off in your ski boots.
The potential amounts of fresh snow are likely to be enough for the Oracle to make an appearance and are already causing powder panic on the Streif, where extra weather stations have been set up along the course for the World Cup this weekend to ensure that the piste is nice and icy everywhere and that the skiers are not blown away during their jumps. Increased caution is also required for non-World Cup skiers, as the stormy north-westerly winds and fresh snow are expected to significantly increase the risk of avalanches.
The weather makes the (sliding snow) avalanches
The avalanche situation has been generally favorable in recent days, but in Switzerland and Austria there are daily warnings of sliding snow avalanches on steep meadow slopes, with the advice not to stay in areas below fish mouths. Sliding snow avalanches go right down to the bottom and release spontaneously without the help of skiers. As usual, the weather is responsible for the problem:
The first snowfalls fell on unfrozen ground. On New Year's Day it rained widely up to over 2000m and shortly afterwards it snowed again on the snow softened by the rain, so that it was nice and warm under a thick layer of insulating fresh snow and could make itself comfortable to form a greasy layer on the ground. In spring, this effect is created by meltwater seeping onto the ground. As the ground temperature and the condition of the snow close to the ground are decisive for sliding snow avalanches, they can also occur in cold weather, unlike wet snow avalanches, and are less dependent on exposure.
