MUNICH (dpa-AFX) - The south-east of the USA and the Caribbean are facing an unusually strong hurricane season this summer. Very high water temperatures in the eastern Atlantic combined with an expected La Niña phase in the western Pacific favor the development of tropical cyclones, according to reinsurer Munich Re.

"We are expecting significantly above-average storm activity in the North Atlantic this summer," said Anja Rädler, the company's storm and climate expert. "In the past 30 years, we have had an average of 15 named storms, this year we can expect 23 plus or minus 4 according to the weather models." According to the scientist, there is also an increased risk of tornadoes and hail in North America. According to Munich Re, of these 23 plus or minus 4 expected hurricanes, 11 plus or minus 3 could develop into hurricanes, which means gusts of wind force 12 or more.

Hurricanes can cause immense destruction in the Gulf of Mexico, the south-east coast of the USA and in the Caribbean. Hurricane Ian alone caused damage of around 100 billion dollars in September 2022, of which around 60 billion was insured. The Munich-based Dax Group has been documenting natural disasters around the globe for decades with its geosciences department, as this is important for calculating insurance premiums. In general, storms cause higher insured losses in North America than in many Asian countries because insurance density is high in western industrialized countries.

Tropical cyclones - known as "hurricanes" in the Atlantic and "typhoons" in the Pacific - require a sea surface temperature of 26 to 27 degrees Celsius to form. "In the North Atlantic, we have had record high temperatures for almost a year and a half, one to two degrees above the average from 1982 to 2011," said Rädler. As the meteorologist explains, comparatively cool water temperatures in the western Pacific are also a factor that can favor the formation of hurricanes. In the western Pacific, there are alternating phases of warmer and cooler water temperatures, the former known as "El Niño" and the latter as "La Niña".

"This year, the forecasts also seem a little more certain than usual because the water temperatures in the Atlantic are extremely high and are already starting to cool down in the Pacific," said Rädler. "The various weather models are almost unanimous that we are sliding into a La Niña situation in the Pacific this summer." This could therefore begin in July.

Although a high number of storms means an increased risk, it is not automatically synonymous with catastrophic devastation. "A severe storm can also cause serious damage in a rather calm phase. Conversely, many storms do not necessarily mean high damage, as long as these storms do not hit the coast," said Rädler. According to Rädler, the Pacific was comparatively calm this summer, with fewer typhoons than usual./cho/DP/he