Today a small update on the upcoming snowfall. A lot of info is already in the previous weather report, but because there was also some uncertainty, it's time to go a bit deeper into it.
Yesterday the weather models still showed some differences for the snowfall on Friday and Saturday with the ECMWF still with the core of the low pressure a bit further north with less precipitation in the Alps and GFS who went for full snow on the north side on Saturday. Today the ECMWF more or less changed its mind and the core of the low pressure area is now following the same course. Good news, because that means there will be more snow in the Northern Alps than last days' calculations.
The first heavy snow phase from the west has already started with a snowline rising to 1800 to 2000 metres and temporarily even higher with the expected stormy winds. While tomorrow morning (Friday) will be dry again in large parts of Switzerland and Austria and it might even clear up a bit in the inner alpine areas, it will continue to snow all night and tomorrow (Friday) in the French Northern Alps and the west of Switzerland. Later in the afternoon, precipitation will return from the west with a still quite high snowline of 1700 to 2000 metres and temporarily even a bit higher.
Only after the low-pressure area passes from west to east will the wind turn further north and a cold front will finally enable cold air to reach the Alps. After a short snow interlude during the night from Friday to Saturday, the cold front will reach the Alps and the snow line will rapidly drop below 1000 metres everywhere.
Sunday seemed to become a beautiful sunny powder day for all of the areas in the western and northern Alps, but with a northern flow, Austria in particular can expect snowfall at least until noon. Afterwards, it may increasingly clear up here too. The Nordstau areas (especially further east) will remain cloudy for a while longer. The rest of the Alps, including the West and Northwest Alps where it snowed so much, will have a sunny day, but with the large amounts of snow and the stormy winds, you have to be careful with the avalanche danger. So please check the avalanche bulletins before you go out!
Our snow map gives a pretty good picture of the snow distribution until Sunday. The Western Alps between the Ecrins and Wallis / Berner Oberland will get lots of snow in the high mountains (> 2000m). There will be 50 to 80 centimeters of snow on a large scale. Around the Mont Blanc massif, over a metre of snow is possible, but the wind will be very problematic.
Initially, all regions east of Valais will receive only 10 to 25 centimetres of snow, but here the snowfall from the cold front on Saturday will bring 20 to possibly 30 centimetres of snow, locally even more in e.g. Arlberg. The advantage is that this snow will fall with a low snowline.
So the question is whether wind is really going to throw a spanner in the works with this dump in the Western Alps. Problematic is the snowfall from the west tomorrow, because with the strong westerly flow it can be really spooky higher up in the mountains. Too low and you're in the rain, too high and the wind is too strong and with a white-out and increasing avalanche risk, many high altitude ski lifts will close.
Saturday, during the cold front passage, it can still be very windy higher up, but after the cold front the wind will decrease more and more. So all in all, Saturday's snowfall is a bit more favourable with a lower snowline and after the cold front with less wind, but this situation should certainly not be underestimated either. From Sunday on it will be calm again.
Next week, the calm and warmth seems to return with possibly some increasing snow chances from the middle of the week, but these developments are still very uncertain at the moment.