WeatherBlog 13 2025/26 | Cold air and warm water

Current situation and outlook

Our colleague the PowderOracle is not entirely satisfied, but is still reporting südstau. An area of low pressure with a core west of France is extending its sphere of influence into the Mediterranean and producing a south-westerly flow with corresponding precipitation on the southern slopes of the Alps. Rain and snow are likely to spread to the northern side of the Alps during the course of today, Wednesday, although the amounts will remain manageable. On Thursday, it will gradually become sunnier from the west. The Atlantic will remain active and there will be no stable high pressure for the time being. The weather will remain "changeable" at the weekend, with some unproductive snowfall. At the beginning of next week, the next strong Atlantic trough could bring another southerly storm, including alarm options.

The current low-pressure activity in the Atlantic is being driven by cold air masses over the north-east of the American continent, which are causing very low temperatures in some areas, lots of snow, around 10,000 canceled flights and millions of power outages.

In fact, the last visit by Arctic air masses was not so long ago here in Germany either. We think back to WB 9 and WB 10 and the cold weather phase after Christmas, for example. The basic weather constellation was comparable to the current situation over North America: on the eastern flank of a blocking high reaching far to the north, cold air masses from Arctic latitudes were able to penetrate far to the south. In the Alps, there is a lack of moisture to turn cold air into snow. In south-eastern Europe, on the other hand, there was around half a meter of snow in the first week of January, as the cold air over the Mediterranean was able to collect moisture and then dump it in Croatia and Turkey, for example.

In North America, the principle is similar, only one size larger and often somewhat heavier as a result (colder, snowier, more widespread). The land mass in the west, over which cold, continental air flows, is larger and the supply of cold air tends to be more persistent than here. To the east lies the Atlantic, which is still warmed by the Gulf Stream along the coast and represents a virtually endless source of moisture. The cold air masses therefore flow onto the warm Atlantic, collect moisture and immediately form low-pressure areas. Depending on their exact position, these then sometimes rotate back to the coast as a "Nor'easter" and bring a load of snow and storms from the north-east, after it was often already freezing cold beforehand. The forecast for the coming weekend sees potential for such a Nor'easter.

Here, in the more or less central Alpine region, we don't have a comparable combination of a large continent in the (north)west and the sea in the east and therefore no weather conditions of exactly this kind. When we get very humid air from the Atlantic in westerly weather, it is always relatively warm. If we get cold, arctic air, we don't have the moisture we need for a lot of snow.

For once, however, we don't want to moan but are happy about the proximity to the Mediterranean and the current alarm. Sometimes, as we all know, fast food is just the thing!