The WeatherBlog was asked why it was so warm last weekend, even though the weather was somehow coming from the north. We'll start with the related question of why it was so windy and generally uncomfortable in the first place. The long-standing purple blob of cold air over Canada was shifted a little to the east by a high reaching far to the north in the west of the North American continent (nice weather in AK?).
From here, the blob can virtually run out into the Atlantic and very cold air in combination with rather warm water can have a stimulating effect on the development of low pressure. In combination with the strongly pronounced Azores High and Icelandic Low, this resulted in Elon and Felix, two storm lows that effectively worked together to give us a meteorologically interesting weekend.
The current had a small north föhn component due to the poor corrugation over Central Europe, which caused north föhn and also some accumulated precipitation (first rain, then a little snow). Although this was somehow a northerly flow, the air masses were originally not really from the north, but rather from subtropical regions and correspondingly warm. If you then add in the effects of the foehn, it's surprisingly easy to reach over 20°C in January.
Note the similarities to Hurricane Kyrill, which incidentally reached similarly high temperatures.