WeatherBlog 22 2023/24 | Another southern storm to end the season

Current situation and outlook

The Alps are located in a warm southerly current, which brings us Föhn (north) or clouds and precipitation (south). The relevant low-pressure area lies to the west of France and extends far to the south, where it can collect warm air and Saharan dust. Both are then transported directly to Central Europe. The Föhn was already very present over the weekend, as the PG team was able to verify in person at the end-of-season meeting in Engelberg. 

In the eastern Alps and generally on the northern side of the Alps, the weather will remain relatively warm and dry today, Wednesday. However, it will become increasingly wet in the south, the further west the more so. The south-western Alpine arc will get another very good load of fresh snow at high altitudes between Wednesday and Thursday. Without consulting the oracle, we dare to say that a metre here and there is within the realms of possibility. The snow line is somewhere around 2000 metres. On Thursday, it will remain wet in the south and comparatively dry in the north. A cold front will move through on Friday and the current will turn to the north. This means that there will also be precipitation on the northern slopes of the Alps, with slightly cooler temperatures. The weather will gradually calm down in the south. The forecast for the weekend looks changeable some showers here and there.

• The images that we often integrate into the WeatherBlog and traditionally also label with outstanding paint skills are visualisations of model data. Weather models calculate what will happen in the future. To do this, measurements - including those from satellites - are fed into the model. Based on the knowledge of the current state of the atmosphere, the model computes what is likely to happen in the future. This can then be visualised either for one point on the earth over time (see meteogram), or for a point in time at many different grid points in the form of a map (as in the image above). The maps of the geopotential, which the WeatherBlog frequently posts, show the large-scale pressure distribution of atmospheric layers that are relevant for the general weather situation (500hPa correspond to an altitude of around 5500m). You can therefore see high and low pressure areas and draw conclusions about the direction of flow - currently, for example, about the foehn-like southerly flow east of the low in the Atlantic. 

• The data shown in the PG weather map also comes from a weather model (ICON). The snow depth map is not a direct observation, but is calculated by the model. The data for the current date also comes from the model. The model is always only an approximation of reality and has all possible uncertainties. The spatial resolution is important here. This determines how much the model knows about the topography and whether, for example, it can distinguish between individual terrain formations or only sees entire mountain ranges.

• We don't know what the next winter will be like, but it's sure to come!