As I mentioned the day before yesterday, today an extra update on the current and upcoming snowfall. You can read all previous info and details about this snowfall here. In the French Alps, we see that it has already snowed a bit in many places. Most of it seems to have fallen in and around the Écrins-Oisans regions for now. The snowline was still far from low everywhere, that will only happen tomorrow. As expected, the centre of gravity of the snowfall shifted to the southern Alps today. In Lombardy, meanwhile, it is already snowing and later today this snowfall will extend further eastwards. In the northern Alps, a powerful föhn prevails higher up, with wind speeds reaching above 100 kilometres per hour. A round of webcams:
From tonight, not only more snow will follow for the southern Alps, but also the French Alps (and the rest of the northwestern Alps) can look forward to quite a bit of snow along with some cooling. The snow amounts even increased a bit. In the southern Alps, the southern areas will see a snowline of around 1,500 metres, the areas towards the Alpine main ridge significantly lower to even below 1,000 metres. In much of the southern Alps, from Engadin/Lombardia and the areas east of it, 20 to 30 centimetres of snow could fall, the southern regions even a bit more and as I wrote the day before yesterday the Julian Alps higher up possibly up to a metre of snow.
In the north-west Alps, it is especially the French Northern Alps (from Écrins-Oisans and northwards) and western Switzerland (Vaud, Valais) that get a good amount of snow. Over half a metre of snow could fall here through Tuesday. Locally also some 10 or 20 centimetres more! From tomorrow, considerably colder air also flows in, lowering the snowline here too! East of the Bernese Oberland, the amounts decrease somewhat. Up to the Arlberg, some 20 to really maximum 40-50 centimetres could fall. Some models are still somewhat reluctant to calculate these amounts this far east.
Going even further east in Austria, we see that most areas are in the shadowside of this snowfall with this north-westerly flow. Here the amounts remain limited, but it is certainly a refresher. East Tyrol and western Carinthia (especially around the Tauern) can still get quite a bit with around 20 to 30 centimetres. The same goes for the northern areas that still benefit a bit with a western flow, such as the Hochkönig and Dachstein massif.
As a reminder, a risk not to be underestimated for the time ahead: among others, SLF warns of risky conditions due to this snow falling on a tricky old snow layer. We find this old snow problem in large parts of the Alps, so be careful. In addition, the strong westerly flow can cause wind slabs especially higher up. Therefore, check the current avalanche reports before heading out.
The impact of the warm front on Tuesday night that I mentioned already seems limited. Around 5 centimetres of snow could fall in the north-west Alps, with the snowline initially still down to the valleys, but soon rising above 1,500 metres at the alpine edge. Earlier calculations showed more rain for the lower-lying areas, but it no longer looks so negative. Most of the precipitation passes to the north of the Alps.
Wednesday follows with a cold front the second part of the same low-pressure system over the North Sea. Winds pick up considerably as the front passes. The snowline again drops from 1500 metres to around or just above 1000 metres and some 10 to 20 (and locally 30) centimetres of snow could probably fall in the north-west Alps.
I am still closely following the developments after Wednesday. The weather models are keeping the suspense going as the differences are still very large. We see the calculations diverging considerably from Thursday onwards. The GFS shows a southwest flow returning with high pressure building, keeping it pretty much dry until at least early next week. The European model, however, calculates a different setting with a completely different result for the Alps. Here, the flow is more westerly, allowing a new frontal system to take hold of the Alps. This would mean that immediately after the cold front on Thursday, we would face another warm front during the evening. In doing so, we should then expect a rising snowline during the night into Friday, especially at the alpine edge (inneralpine may be able to hold on a bit better), and lots of snow again. Even after that, the ECMWF continues the succession of fronts with quite a bit of precipitation for the Northwest Alps, which would immediately mean PA#4. Let's see what the models present us with tonight and tomorrow morning! Another weather report tomorrow!