The southwest and parts of southern Poland have been flooded. The most difficult situation is in Lower Silesia, including the Kłodzko Valley and Opole regions. In Kłodzko, the situation has calmed somewhat, with water levels dropping, but the city remains without power. The situation in Głuchołazy has been dire, with two bridges washed away. Most of Nysa is cut off from the outside world. Wrocław is preparing for the surge.
Exceptionally Wet Genoa Low
The intense rainfall that has affected our part of Europe is due to a low-pressure system from northern Italy, known as the Genoa low. According to the meteo.pl service, this low brings heavy and prolonged rainfall and forms when cold air from the north meets warm and moist air from the Mediterranean. The critical factor here is that this Mediterranean air was exceptionally moist this time. This was because the sea surface temperatures this summer were record-breaking. This is well illustrated by a graph posted on the "Świat Wody" (Water World) Facebook page, run by ecohydrologist Dr. Sebastian Szklarek.
Where Did All the Moisture in the Air Come From?
Scott Duncan, a Scottish meteorologist tracking climate-related phenomena, described the chain of events. Here are the main ingredients of the recipe for flooding in Central Europe:
- First, the aforementioned "heatwaves" over the sea. Warm air can hold more water, and here, we also had increased evaporation, fueled by record-high sea surface temperatures. This moisture accumulated in the air.
- Then, in early September, an unusually cold air mass for this time of year moved over a large part of Europe from the north. This created conditions favorable for the formation of weather fronts, and they were stronger than usual on both sides.
- Factors also emerged that led to the "trapping" of the low-pressure system in one place for several days. This meant that the moisture it carried fell over a concentrated area. "Weather factors in Europe are supporting an extreme combination of variables that can remain trapped for days," the meteorologist wrote.
- The "trapping" effect was further enhanced by the geographical layout of Central Europe, particularly the mountains (known as orographic enhancement).
- In early September, the moisture from the Mediterranean moved towards the Black Sea, which was also warmer than usual, creating an "atmospheric river."
All of this caused the Genoa low to become stronger than usual. "In some parts of Central Europe, no similar weather phenomenon has ever been recorded before. Not only in September, but in any other month," concluded Scott Duncan.
Where Are the Climate Changes?
It's too early to assess whether and to what extent the current weather situation in southwestern and southern Poland is related to climate change. However, as climate change progresses, we can expect more frequent and intense extreme weather events.
The Genoa low is a typical meteorological phenomenon, but the frequency and intensity of such weather events are increasing. The droughts and torrential rains that are increasingly affecting our country are a textbook example of what happens due to the emission of massive amounts of greenhouse gases, as scientists have warned for decades. The preventative steps we need to take are known and outlined in various climate and biodiversity conferences. So why aren't we implementing them?
- said Prof. Dr. Piotr Skubała from the University of Silesia in Katowice, and a member of the advisory State Council for Nature Conservation.
