This week will be full of contrasts. It will snow heavily above 2000 meters on the south side of the Alps, but it will be mild with heavy winds on the north side of the Alps. The front will hit the Alps in two phases. The front will come from the south - southwest on Monday and Tueday, but will come from the southeast (retour d'est) on Wednesday and Thursday. The incoming air isn't cold. The snow cover will therefore mainly grow above 2000 meters in the southern French Alps, the Italian Piedmont and Lombardy and in the ski resorts of southern Switzerland in the next couple of days.
In this forecast:
The snow sandwich which I talked about earlier passed the Alps on Saturday. That resulted in 20-40 centimeters of fresh snow on the south side of the Alps and 5-20 cm, locally even 30 cm in the northwest and the north of the Alps. It was the first of a total of three dumps this week. The sun came out on Saturday afternoon in the west and the wind kicked in on Sunday. It started snowing again on the south side of the Alps in the night to Monday.
The second dump of the week arrived in the night to Monday. A current from the south - southwest is bringing fresh snow on the southern side of the Gotthard, the Monte Rosa and the Ecrins. You can see this on the radar images. A local measuring station has recorded 72 cm of fresh snow since Saturday and the webcam of Airolo shows some fresh snow as well.
It's snowing again in the southern French Alps and on the border between Switzerland and Italy and it will keep on snowing today and Tuesday. The current came from the southwest today, but will turn more to the south. Jetstream maps always come in handy in those cases. Check out the map below from this morning.
The jet stream marks the boundary between cold air from the north and warm air from the south and is often the highway storms use to reach Europe. If you follow the red stripe on the map below you can see that the current is southwest to south today. Clouds are pushed against the Alps from that direction. The hit the highest peaks of the French southern Alps and the peaks on the border between Switzerland and Italy first. Check that out on the map below.
Those are the places where you can expect the most snow (or rain) today and tomorrow. The snow line is still around 1200-1600 meters, but in will rise towards 1800-2000 meters on Tuesday. The snow will definitely fall. The dump today and the one on Tuesday will bring 20-65, locally 90 cm of fresh snow above 2200 meters.
But while it snows and rains in the south, it is mild and stormy in the north. This is caused by a mild current from the south. This causes the clouds to hit the Alps and the temperatues to drop on the south side of the Alps. On the north side of the main alpine ridge however, the wind will kick in and the temperature will rise. Check it out on the picture below.
Just have a look what's happening today. There are warnings on the south side of the Alps for heavy precipitation and snow above 1200-1600 meters. In the meantime the wind kicks in on the north side of the Alps.
The temperature in the Föhn valleys (the valleys that will have to deal with the heavy winds from the south the most) can rise up to 20 degrees Celsius in the next 48 hours, while at the same altitude on the southern side of the Alps it's just 3 degrees Celsius. Huge differences!
The Föhn from the south will on till Wednesday, but will get weaker after Wednesday.
The weakening of the southern Föhn is caused by the rotation of the current. A look at the expected jet stream for Wednesday explains a couple of things. The jet stream will come from the southwest to south today, but will come from the southeast on Wednesday.
A current from the southeast is also called the famous retour d'est. Snow is coming through the Po Valley from the east to southeast and hits the highest peaks on the border between Italy and France and Italy and southwestern Switzerland. It will also snow heavily in the Italian Piedmont and the bordering ski areas in France and Switzerland. Think of ski resorts in the Queyras, Montgenèvre, Valfréjus, Bonneval sur Arc and the most eastern part of Val d'Isère in France and resorts near the Simplon, Saas Fee and Zermatt in Switzerland. But the most snow will come down in the resorts on the Italian side of the border and especially in the Piedmont.
You can expect the most snow (or rain) in those resorts on Wednesday and Thursday. The snow line will be around 1700-2100 meters and dry snow will only fall above 2300 meters. The dump of Wednesday and Thursday will bring 40-100 cm, locally even 150 cm of fresh snow above 2400 meters.
It will stop snowing on Friday, the wind won't be that strong anymore, the sun will come out and you can definitely ride some powder above 2200 meters. Ski touring from the Col du Montgenèvre, Agnel, Sestrière, Simplon and Lukmanier is possible. More ski resorts will open in the weekend of the 25th of November on the south side of the Alps. PowderAdvice for the weekend will follow the next couple of days. Keywords: southern Alps en high altitude.
Stay stoked. Morris