The Alps will be more and more under the influence of a southern current this week. The high pressure area that is still above the Alps will be pushed to the east in the coming week. An active storm depression above the Atlantic will thus have the chance to lead precipitation to the Italian Piedmont with a powerful southern to south-eastern current.
The week starts with high pressure above the Alps. The days are sunny and very mild, while it cools down considerably during the clear nights in the high alpine. The transition from summer to winter is clearly visible during the clear late summer weather. Higher up on the mountain it's already autumn. The trees are changing color and the larches are slowly losing their needles, but there is no question of winter.
The Alps will have to deal with a southern current later in the week. Storms over the Atlantic and high pressure over Russia ensure that cold air from the north can go south. At the same time, warm air from the southeast of Europe is on the move, resulting in a strong current from the south.
As a result of the south to south-eastern current there is a Stau situation building up south of the Alps. Due to the orographic cooling and the supply of some cooler air from the east, things get a bit colder there. The combination of humid air, lower temperatures in the upper air and the rapidly rising Alps can cause a lot of precipitation. This will result in some fresh snow in the Italian Piedmont and Aosta above 2500-2800 meters. Below that elevation you expect a lot of rain.
Even more intense is the precipitation calculated for the south of France where the colder upper air layer is fed by the warm Mediterranean sea. The picture below shows the precipitation for the Alps, but even better the intense precipitation for the south of France.
Stay stoked, Morris