Once again the webcams in the Alps show bright blue skies. On the northern side of the Alps, we still see low-hanging clouds at the alpine edge due to the weak wind conditions, as here in the Rhine Valley for example, but all over the Alps it is another sun-drenched day and temperatures in the valleys can once again rise to around 15 degrees.
As we know, the fine weather is caused by a strong high pressure area over central Europe. Today, the core has already moved a bit more to the east and tomorrow the high pressure area will weaken a bit more. This will mean that we will already have to deal with some more (mainly high) clouds tomorrow, but during the day the sun can still shine abundantly. However, it will already be a little bit colder in the northern Alps.
As a new high pressure core from the Atlantic exerts a little more influence, the Alps enter a more westerly flow and the Northern Alps may receive some precipitation from Friday. Nearby high air pressure over southern Europe does work against the snowfall somewhat. The jet stream lies just north of the Alps, so it will still be quite mild. The snowline can certainly rise to around 1600 - 1800 metres at the alpine edge. However, the question is whether as much will fall as our weather model shows below. It's far from certain at the moment and I am not yet entirely convinced. It depends on the precise flow whether more stau can take place or whether most precipitation passes just north of the Alps.
On Friday, precipitation is negligible anyway with at most some light precipitation at the alpine edge, but from Saturday onwards, the models still vary widely. In western Switzerland, it may even stay completely dry. The American model shows significantly less precipitation and also limited to the areas east of Tyrol. ECMWF and ICON are more positive in that respect, with snow on the north side from central Switzerland to eastern Austria and amounts that could reach 20 to 30 centimetres in, for instance, Arlberg and northern Salzburg. However, further inland Alpine precipitation amounts will rapidly decrease again and there may also be wider clearings in between. Sunday may also see some snow deeper into the Alps. The snowline will be an issue, as it only cools slightly again on Sunday.
After the weekend, things get drier again and the sun once again gets plenty of room. For several runs in a row, a tipping point may follow later in the week. With a high-pressure area near the British Isles, cold air could flow from the north towards the Alps. Whether this will also be accompanied by precipitation and a possible Nordstau is still very uncertain. In any case, the first signs are already hopeful, but it's certainly not a done deal yet. In the GFS ensemble for Innsbruck, we can see that the main run goes full for the cooling this morning, but that the ensemble mean and the control run don't quite want to follow suit yet. You can read more about the ensemble forecast here.