First of all, best wishes to everyone for the new year! Let's hope for a snowy second part of the winter so that we quickly forget the past few weeks that included rain and extraordinarily high temperatures. As I mentioned before the weekend, we seem to be slowly returning to a more changeable weather pattern. Especially from next week on, things seem to get considerably more changeable in the northern and western Alps.
The warm front on Friday was another major setback for the north-west Alps. Many lower-lying areas that were already struggling with a severe lack of snow received another substantial amount of precipitation in liquid form. Locally 10 to as much as 25mm of rain. Le Grand Massif in Haute Savoie, for example, has now even announced that it will have to close for a large part due to a lack of snow. These are things we really don't want to see in January. The webcam images in this corner of the Alps speak volumes. In the high mountains, although there is now a good base, conditions are not yet anything to write home about either.
The expected precipitation for tonight and tomorrow will unfortunately not make a dent. The amounts have been scaled down some more over the weekend. The cold front has already weakened to the extent that it will produce little more than a cosmetic layer. In the French Northern Alps and western Switzerland, it could still reach 5 to 10 centimetres locally due to some accumulation, but for most areas in the Western and Northern Alps it will remain at a few centimetres with a snowline of around 1700 metres.
Tomorrow and Wednesday, the Alps will see increasing high-pressure influence again due to a high-pressure area over southern Europe. With a low-pressure area moving through Scandinavia towards Eastern Europe, the flow in the Alps temporarily turns to northwest. On Thursday, this will make it changeable with some showers, especially on the northern side. I do not expect much more than 5 centimetres. Although it cools slightly, the northwesterly flow is still quite mild, so the snowline will remain around 1,500 to 1,800 metres. The somewhat cooler air will soon be driven out again by a new warm front.
Some improvement seems to be in sight from the second decade onwards. In fact, our forecast shows some red colours again from the beginning of next week. It shows the potential of this situation, but there are still several factors that could throw some spanner in the works. We have to deal with a strong westerly flow, with a succession of low-pressure systems with warm- and cold fronts providing more precipitation, but also a strongly fluctuating snowline. We also see this in the US model's ensemble for Grenoble as an example. That it will become considerably more changeable from the beginning of next week is now clear, but we also see some temperature fluctuations next to a big spread in the temperature and precipitation signal. Hopefully I will be able to go into a bit more detail about this changeable phase on Wednesday.