We are currently in the middle of PA#1. The Western Alps had to deal with a second wave of snow today. Several roads and villages are closed and on a large scale there is avalanche danger 4 (temporarily even 5!).
In this weather report:
The West Alps are once again hit with massive amounts of snow. On a large scale, the second wave of snow has brought half a meter of snow on top of the huge amounts that have already fallen. The snowfall caused a lot of inconvenience, but Rogier was on the road today in the Pelvoux ski area and showed how wonderfully deep it was there. Due to the high avalanche danger he stayed far away from slopes steeper than 30 degrees. Steeper terrain is simply a big no-go at the moment. In the weekend, the higher areas in particular will probably not be able to open all the lifts due to the large amounts of snow and the avalanche risk.
It's not only the French Alps that are doing well. As expected, the snowline rose sharply in the Pyrenees last night with the arrival of considerably milder air. Together with the enormous amounts it resulted in lower lying regions having to deal with flooding, landslides and wet snow avalanches. In Laruns in the western Pyrenees no less than 186 mm of rain fell in 24 hours, a record for this station. A little further on, the village and ski resort of Cauterets is cut off from the outside world due to a landslide. Higher up, snow records have been broken in several places.
The snowline is now dropping significantly and locally there could be another 40 centimetres above 1600 metres. Not only in the French Alps is the avalanche risk extremely high, also locally in the Pyrenees avalanche danger 5 has been issued.
For the weekend little has changed compared to what I wrote yesterday. The Southern Alps are going to have a nice sunny day. In the French Northern Alps it also opens up during the day, but possibly a bit slower than expected. The rest of the Northern Alps will have to deal with some (light) snowfall tomorrow, which could reach 10 to 15 centimetres in the stau areas. Sunday will be sunny for a large part of the Alps. In the Northern Alps, clouds will approach from the northwest during the day as a result of a warm front.
On Monday, the warm front may bring some precipitation to Austria. Above 1200 to 1400 metres, this precipitation will fall as snow, but large quantities should not be expected. In the following days, the high-pressure area will take over completely and will increase in strength considerably. It will be considerably milder than last week, but it will remain dry. In the low-lying valleys, an inversion (low-stratus deck) may develop, which will only slowly dissolve during the day.
The jet stream is the culprit. The past snowy phase was partly due to a fairly southerly jet stream that allowed depressions and low temperatures to reach the Alps. Next week, as you can see above, the jet stream will be much further north and will stay there for a while, allowing a powerful high pressure area to settle over Central Europe.
In the long run, a few model runs in a row seemed to make something possible for Austria. Seemed ... because while in the last model runs the high pressure area at the end of next week seemed to move westward and thus cleared the way for a northerly flow for Austria, in today's new runs this is not visible everywhere anymore. There are still some signs of a change at the end of next week with especially the Eastern Alps hoping for a cold outbreak with snow, but for now this is still a bit too far away. This strong high-pressure setting might just last a bit longer.