It is currently still mild in the Alps. In fact, today it will be full spring again with temperatures reaching above 20 degrees in the valleys. Here, the grass is already starting to grow again and winter seems to be retreating back to the high mountains. But it only seems, because from the weekend a major weather change seems imminent. PA#11 is on the way!
With a south-westerly high, very mild air will be brought to central Europe. This means another spring-like warm spell in the Alps. Tomorrow will also remain mild, but the sun will not be seen as often.
From the west, it will become increasingly changeable. Initially, this is still accompanied by a fairly high snowline, but also by little precipitation. Tomorrow it will remain dry and warm almost everywhere, but the day will get a lot cloudier, especially in the north-west Alps. On Friday, a cold front approaches with the first precipitation.
Initially, quite warm air is still present, so the snowline will be around 2200 - 2300 metres. During the evening, the snowline seems to drop below 2000 metres, to around 1500 - 1700 metres altitude. In the higher regions of the French Northern Alps, some 10 to 20 centimetres could fall until Friday afternoon. In the evening and night into Saturday, the precipitation will persist and the amounts here could even increase significantly.
Over the weekend, it remains changeable with snow in the north-west Alps. Saturday afternoon to Sunday morning does see a temporary dry interlude. Last weekend I already wrote about the possible cooling. The real cooling only from Sunday evening from the northwest. The snowline during the weekend could still be around 1,000 to 1,300 metres in the favourable case, but this is not yet completely certain. Above 1500 metres, all precipitation does fall as snow. By Sunday night, up to 50 centimetres may have fallen on a large scale higher up in the north-west Alps. Stormy winds will be a thing over the weekend.
On Monday, the low pressure area already providing snow over the weekend moves further east. On the backside, the way is cleared for a cold snap from the north resulting in a temporary Nordstau. The snowline could possibly end up in the lowest valleys, and a lot of snow could also start falling in the Northern Alps. How much exactly and how long the snowfall could last is uncertain at the moment. High pressure, as so often with this situation, is lurking to suppress the snowfall from the west. In any case, the above snow amounts are good for a first indication. More on this snowfall in a fresh powder alert later this week.