The Mediterranean Sea brings torrential rains and storms in the Alpine region

The effect is most pronounced when the northwest air current meets humid Mediterranean air for the first time – specifically in the west and northwest of the Mediterranean. In addition to parts of the western Mediterranean and the Gulf of Lions Up to five degrees Celsius warmer than usual for this time of yearso that the resulting storms are particularly violent. The warm Mediterranean Sea provides more energy for depression.

More Mediterranean thanks to climate change

The exceptionally high sea temperatures also play an important role in the high rainfall in the Alpine region. The warmer the sea, the warmer the air above it: not only does this mean that more water evaporates, but the air can also absorb more water vapor. On the southern and eastern sides of the depression over northern Italy, warm, moist Mediterranean air flows north and rain falls on the slopes of the Alps.

Such so-called Vb low-pressure areas, which move northeast across the Mediterranean Sea and sweep very moist air northward on its front side, have also caused catastrophic floods in Germany in the past. For example, severe floods on the Elbe in 2002 and 2013. Climate models have shown for years that an increasingly warming Mediterranean increases heavy rainfall in Germany.