Europe floods: Why Storm Boris is so devastating

After a hot start to September, Europe is experiencing record rains and flash flooding in parts of central and eastern countries.

Storm Boris has dumped a month’s worth of rain and strong winds in only one day on large portions of Poland, Romania, Austria, the Czech Republic, and Hungary.

Because of the flooding, the death toll was rising and several people went missing.

Here is why the storm is so deadly.

Storm Boris

Storm Boris, a slow-moving low-pressure system, is currently bringing extreme torrential rain across central and eastern Europe, with more downpours projected until at least the end of Monday.

According to BBC, two reasons why the storm has been so destructive are: 1. moisture pulled up from the Black Sea’s exceptionally warm seas and the Mediterranean combined with chilly air from the north. 2. There is a low-pressure area that is caught between high pressure to the east and west in a blocked weather pattern.

The World Weather Attribution Network concluded that the likelihood and intensity of major flooding events in Europe were rising due to climate change after witnessing severe flooding in 2021.

Fierce rainfall

Most parts of the Czech Republic have been affected as authorities declared the highest flood warnings at around 100 places across the country. The situation was worst in two northeastern regions that recorded the biggest rainfall in recent days, including the Jeseniky mountains near the Polish border.

Towns and villages in the Jeseniky mountains were inundated and isolated by raging waters that turned roads into rivers. Strong winds downed dozens of trees, damaged cars and a number of bridges, and blocked roads and traffic. Jesenik Mayor Zdenka Blistanova told Czech public television that several houses in her and other nearby towns have been destroyed by the floods.

According to The Associated Press, about 260,000 households were without power on Sunday morning in the entire country, while traffic was halted on many roads, including the major D1 highway.

The Oder River that flows to Poland was reaching extreme levels in the city of Ostrava and in Bohumin, prompting evacuations. Almost no trains were operating in the region.

The municipality of Austria’s Lilienfeld, with about 25,000 residents, is cut off from the outside world. Residents were told to boil tap water as a precaution. The situation is particularly dangerous along the Kamp River, which flows into the Danube.

The Ottenstein reservoir on the river functions as a buffer, but exceeding its limits could cause more flooding, experts say. In Vienna, the Wien River overflowed its banks, flooding homes and forcing the first evacuations of nearby houses.

Polish PM Tusk said the situation was “dramatic” around the town of Klodzko, with about 25,000 residents, located in a valley in the Sudetes mountains near the border with the Czech Republic.

In Glucholazy, rising waters overflowed a river embankment and flooded streets and houses. Mayor Paweł Szymkowicz said, “We are drowning,” and appealed to residents to evacuate to high ground.

A bridge in the town collapsed under the flood pressure and a police station building was knocked down in Stronie Śląskie, after floodwaters burst through a dam. Submerged cars could be seen in many places in the Kłodzko Valley region bordering the Czech Republic, while a new flood wave was expected there.

The Polish authorities were also forced to shut the Gołkowice border crossing with the Czech Republic after a river flooded its banks, and close several roads and halt trains on the line linking the towns of Prudnik and Nysa, according to The Guardian.

In the city of Jelenia Gora, which has 75,000 residents, downtown streets were flooded after one of the embankments burst on the Bobr River. Energy supplies and communications were cut off in some flooded areas, and regions may resort to using the satellite-based Starlink service, Tusk said.

Slovakia has declared a state of emergency in the capital, Bratislava. Heavy rains are expected to continue until at least Monday in the Czech Republic and Poland.

Hungarian capital Budapest Mayor Gergely Karacsony has warned, “According to forecasts, one of the biggest floods of the past years is approaching Budapest, but we are prepared to tackle it.”

Death toll

Several Central European nations have already by hit by severe flooding, including Austria, the Czech Republic, Poland and Romania. Slovakia and Hungary might come next as a result of a low-pressure system from northern Italy dumping record rainfall in the region since Thursday.

Over the past two days, six people have died in floods in southeast Romania. The worst affected region was Galati, where over 5,000 homes were damaged.

A firefighter died after “slipping on stairs” while pumping out a flooded basement in the town of Tullin in Austria.

In Poland, one person was presumed dead in floods in the southwest, Prime Minister Donald Tusk said on Sunday.

In the Czech Republic, four people who were swept away by waters were missing, police said. Three of them had been in a car that was swept into a river in the northeastern town of Lipová-lázne, while another man was missing after being swept away by floods in the southeast, The Guardian report claimed.

Vb conditions

The term “Vb (pronounced five-B weather conditions) weather conditions,” which is rarely used in English media, was initially used in 1891 by German meteorologist Wilhelm Jacob van Bebber, who numbered common low-pressure system courses in Roman numerals, according to German-outlet DW.

The designations Va, Vc, and Vd have now become less common.

However, meteorologists sometimes refer to unusual pressure systems as Vb when describing the severe rains and frequently catastrophic devastation that can occur in Europe, the report explained.

Low pressure systems that travel from west to east throughout the continent frequently influence the weather in Europe. However, in a Vb weather setting, the low pressure system’s route alters: because of the cooler air masses over western Europe, the low pressure system flows towards the Mediterranean Sea. These low-pressure zones in the Mediterranean are also referred to as Genoa, Adriatic, or Balearic lows, depending on the location of the core.

Across the Czech Republic and Poland, and up through Scandinavia, the low pressure area forces extremely humid air from the Mediterranean region past the eastern edge of the Alps. The system spreads across Europe, bringing with it considerable precipitation. This was also seen during the flooding in June 2024 in eastern and southern Germany.

While very warm southern and cold northern air masses strongly exchange in the spring and autumn, Vb weather conditions may develop anytime, according to DW.

A well-known example of a Vb weather pattern is the August 2002 “flood of the century” that happened close to the Elbe river in Germany.

Climate change is predicted to result in increasingly extreme weather in Vb.

Evacuation and rescue operations

In the city of Opava, up to 10,000 people out of a population of around 56,000 have been asked to move to higher ground.

Rescuers used boats to transport people to safety in a neighbourhood flooded by the raging Opava River, according to AP.

“There’s no reason to wait,” Mayor Tomáš Navrátil told Czech public radio, adding that the situation was worse than during the last devastating floods in 1997, known as the “flood of the century.”

Thousands of others also were evacuation in the towns of Krnov, which was almost completely flooded, and Cesky Tesin.

In Jeseniky mountains, the military sent a helicopter to help with evacuations.

Authorities declared the entire state of Lower Austria in the northeastern part of the country a disaster zone, while 10,000 relief forces have so far evacuated 1,100 houses there. Emergency personnel have started setting up accommodation for residents who had to flee their homes due to the flooding.

According to the report, Austrian Chancellor Karl Nehammer said the situation “continues to worsen.” He said 2,400 soldiers were ready to support the relief effort in Austria. Of those, 1,000 soldiers will deploy to the disaster zone in Lower Austria, where dams were beginning to burst.

In Poland’s Klodzko, helicopters were used to pick up people from roofs in a few cases.

With inputs from agencies