Today an update on PA#5 and the upcoming heavy snowfall in the Northern Alps. Most of it I have already covered the day before yesterday in my weather report. Now a short update with the focus on the wind, the snow amounts, the avalanche danger and where to go.
The past few days have been a nice warm up for the real snow dump coming up. In Zauchensee, for example, it was already really great with a bit more snow than expected, but also in other areas in the region it was just deep enough to have a lovely powder day. Fortunately, there's still a lot more to come, because in this region, among others, it will get a lot deeper with 50 to 100 centimetres of snow in the coming days.
The stormy winds are present again today, especially in the Eastern Alps. It has everything to do with the jet stream which blows today at high altitudes over the Eastern Alps. In most ski areas, many of the higher lifts will are closed due to the strong winds. This stormy wind will continue to blow for the next few days and the ski resorts will have many problems due to the position of the jet stream. Tomorrow in particular, the jet stream will be much more westerly, which means that the French Alps will finally get some snow again.
Tonight it will still be fairly calm because of increasing high pressure, but tomorrow in the course of the morning it will start snowing again from the northwest. At the same time as the precipitation front passes, the wind will increase enormously. In the French Northern Alps it will also snow for a while until the night from Monday to Tuesday the air pressure rises again and the snowfall decreases. Here I expect some 10 to 20 centimetres, but if you go further east, the amounts will increase quickly.
The first wave of snow will almost seamlessly change into the second, but Tuesday afternoon the intensity of the snowfall will temporarily decrease a bit. On a large scale from Central Switzerland to Eastern Austria, 30 to 60 centimetres of snow may fall with a snowline that will reach most valleys. On Tuesday, Switzerland in particular seems to be a bit more wind-swept, but in the remaining parts of the Northern Alps you have to reckon with stormy winds, closed ski lifts and a high avalanche risk.
During Tuesday night, the intensity of the snowfall will increase again and it can start snowing a lot. This wave of snow will give 30 to 50 centimetres of snow on a large scale. In the French Northern Alps, it won't be as heavy, but still some 10 to 20 centimetres of snowfall is possible. In the Nordstau areas from Central Switzerland to Austria, I expect a meter of snow, with the Arlberg even exceeding that. Wednesday, milder air will enter from the west, causing the snowline to slowly rise. In the Western Alps it will end at about 1000 to 1200 meters and further east at about 700 to 1000 meters.
So there are a number of factors we need to take into account. First of all, the wind will play a huge role. The powerful jet stream is flowing directly over the Alps and the strong northwestern flow is going to spoil things for higher altitude ski resorts. So don't go too high up in the coming days. The avalanche risk will be sky-high due to the combination of this storm and the large amounts of snow. Don't dive straight into steep terrain and read the avalanche reports well before you head out!
The front runner in terms of snow amounts seems to be Arlberg with up to one and a half metres of snow according to the German ICON model. The other models are predicting over a meter of snow. Our weather model gives a good picture of the distribution of precipitation until Wednesday and identifies the hotspots quite well. Between central Switzerland and the east of Austria, you'll be lucky almost everywhere in the coming days. So be aware that high altitude ski resorts (e.g. Obertauern and Ischgl) might have to stay mostly closed on Monday and Wednesday. So stay a bit lower. Check the wePowder Guide for the endless possibilities in these regions.
Finally, in order to be able to take part in the search for a good destination for the coming week, I would like to talk about Thursday. The Alps will be in calmer waters and the wind will decrease significantly. While in Austria it may continue to snow lightly, in the Western Alps it clears up in more and more places. Please note that even on Thursday the avalanche danger will be very high in many areas. Long-term coldness is not to be expected, because soon after the Nordstau, considerably milder air will arrive from the west on Thursday, with temperatures of up to 10 degrees at 1500 metres in the Western Alps. In Austria it will stay cold a bit longer.