Starting tomorrow, after a long dry period, it's time for a big Nordstau in Austria. Locally there might be a meter of snow, so it's time for a new Powder Alert! Note that not all areas in Austria will get the full load. Of course the areas of Osttirol and Carinthia are on the wrong side of the alpine ridge, but the west of Austria (Vorarlberg and Tirol) will probably also get less of this snowfall.
We can be brief about today: it's the last calm day before things get started in Austria. High air pressure dominates over the Alps and it will be sunny everywhere. During the afternoon clouds will approach from the west. The Nordstau is in the starting blocks, but before that happens, a small upper level low will create a southwest flow with some snowfall in the French Northern Alps and Switzerland tonight. It's a very small-scale feature which, with a maximum of 5 centimetres, will not produce much more than dust on crust.
In the course of tonight, a cold front will soon follow from the northwest, which will ensure that the entire Northern Alps will be covered in snow. Until tomorrow night, 10 to 20 centimetres of snow will fall between Central Switzerland and the Arlberg. In the course of Friday, the main part of the snowfall will move to the Eastern Alps, making it snowier here as well.
On Friday, the intensity of the snowfall decreases from the west and it also temporarily snows less in Austria. In the Western Alps it clears up and also in most areas west of Innsbruck it stops snowing. East of Innsbruck, especially in the stau areas, it could continue snowing all day long, which could bring 20 to 30 centimetres of snow until Friday evening. During the night from Friday to Saturday, a warm front with a huge amount of snow will follow. Around the Salzburgerland region, this snowfall could last until the end of the weekend (and maybe even longer), causing local snow accumulations of a meter.
I've included the ECMWF model above because I'm not convinced of our weather model. For days now, the strongest snowfall is pretty consistently calculated for the east of Austria, but our weather model doesn't really show that. So don't focus too much on the exact snow amounts you see in our ski area forecast! Especially for Tyrol and Vorarlberg they are too positive. I expect the most snow in the stau areas around the Dachstein massif and the Totes Gebirge. This means a metre of snow could fall here by Sunday evening.
It is important to keep an eye on the timing of the snowfall. It doesn't happen right away, starting Thursday. The heaviest snowfall will come on Saturday (possibly half a meter of snow in the stau areas) with the passing warm front, which means it will only get really deep from then on. Also Sunday it will probably snow all day in the east of Austria with especially in the stau areas again 20 to 30 centimetres of fresh snow. Further developments early next week are still very uncertain. The European model has it snowing (lightly) for a couple of days in the Eastern Alps, but the American model chooses a drier path with possibly already some sun on Monday and Tuesday.
Please note that especially on Thursday and Saturday during the front passages the north wind picks up considerably! In combination with the heavy snowfall on Saturday Wind slab formation becomes a serious problem in the Eastern Alps. Avalanche danger will be high, so please check the local avalanche bulletin before diving into the deep powder! In any case, it is wise not to go higher up on Saturday and to stay far away from steep terrain. Despite the milder air, the snowfall line remains below 500 meters, which means that even lower stau areas will be covered in snow.
The Salzburgerland and Oberösterreich will get loads of snow on Saturday. On top of the 20 to 30 centimeters (locally possibly more) that will fall until Friday, there could be another 30 to 50 centimeters of snow. Because of the strong wind, it is not wise to ski in steep and exposed terrain. From Sunday onwards, the wind speed will be lower again, but the stau areas in the east of Austria will continue to get snow. Also on Sunday, please be careful: the avalanche risk will still be very high. Hotspots for snowfall are for example:
It will be very deep in these places, but also consider some low skiing areas like: