PA4: Snowy week with 30 to 80 cm on a large scale

In France, Switzerland, and Northwest Italy, a fresh layer of 10 to 30 centimeters fell in the past 24 hours. In the coming days, almost the entire Alpine region will be affected by fresh snow: time for Powder Alert 4! In this alert:

• A Genoa low with a snow zone is moving further east today.
• Monday and Tuesday, new disturbances will bring a lot of snow, especially in the Western and Southern Alps.
• From Wednesday, it will become more slightly more stable but snowy surprises remain possible.
• Watch out for the increased avalanche danger!
• The snow line is between 1300 and 2000 meters, so it will be very wet in the valleys.
• A high-pressure ridge will bring a few dry and fairly cold days starting from Friday.
• Where can you expect the best conditions?

Snow zone moves east

On the weather map above, we see another hurricane depression near Ireland bringing unstable and initially mild air to Europe. Another depression over Northern Italy already caused snow in the Western and Southern Alps, and this precipitation will also reach Austria and the Dolomites in the afternoon. Around and south of the main ridge, 10 to 20 centimeters will fall from 1400-1700 meters. Sunny weather dominates in the western half of the Alps and extend eastwards in the afternoon.

Prolonged precipitation on Monday and Tuesday

This Powder Alert mainly concerns Monday and Tuesday. Showery precipitation from the Ireland depression will then push against the Western Alps, and at the same time, a new disturbance will form over Northern Italy, causing sudstau. As it moves away on Tuesday and Wednesday, a small retour d’est may also occur. The precipitation comes in multiple waves and eventually brings fresh snow almost everywhere. The largest amounts are expected in an arc from Trento, over the Swiss Alps to the French Southern Alps. Above 2000 meters, there will certainly be half a meter of snow with possible peaks up to 80 cm. Areas in Austria and the Dolomites can expect 20 to 50 centimeters between now and Wednesday. As mentioned above, this dump will not affect the valleys and lower areas: we start with a 2000 meter snow line on Monday in France, which drops to 1200 meters on Tuesday. In the Southern Alps (including the Dolomites), it is slightly less mild, and snow will fall both days from 1300 to 1700 meters.

Trough brings uncertainty on Wednesday and Thursday

A trough with relative cold in the upper atmosphere and various wandering disturbances will lie over Central Europe on Wednesday and Thursday. It is difficult to indicate where these disturbances will cause snow, but surprises are certainly not ruled out. It will become colder in any case, and where snow falls, it will be down to around 800 meters. In the coming days, we will be able to provide you with more details about this. From Friday or Saturday, the high-pressure lid returns to the atmosphere. Sunny and calm conditions will prevail, allowing the fallen snow to be well preserved.

Where to go?

The French, Swiss, and Northeast Italian Alps and Vorarlberg already have a good base from around 1800 meters. With the fresh snow expected, this is a logical but for now not a safe choice. A layer of heavy wet snow has already fallen, and the next dump will also be quite wet below 2200 meters. Avalanche level 3 has been issued in most regions and this will likely be raised to 4, possibly 5 regionally, in the coming days. I would advise to stay on gentle slopes and/or below the tree line this week and wait for the avalanche danger to decrease. This coming weekend, conditions could be ideal in a large part of the Alps.