Tropical cyclones can cause devastating damage. Signs point to an unusually strong Atlantic hurricane season that could threaten the southeastern United States and the Caribbean.
The southeastern United States and the Caribbean are threatened with an unusually strong hurricane season this summer. According to the reinsurer Munich Re, very high water temperatures in the eastern Atlantic combined with an expected La Niña phase in the western Pacific are favoring the formation of tropical cyclones.
“We expect 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, according to the weather models, we can expect 23 plus/minus 4.” 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/minus 4 expected cyclones, 11 plus/minus 3 could develop into hurricanes, which means gusts of wind force twelve or more.
Damages amounting to 100 billion dollars
Hurricanes can cause immense destruction along the Gulf of Mexico, the southeast coast of the United States, and the Caribbean. Hurricane “Ian” alone caused damage of around $100 billion in September 2022, of which around $60 billion was insured. The Munich DAX group and its geoscientific department have been documenting natural disasters around the globe for decades, as this is important for calculating insurance premiums. In general, storms in North America cause higher insured losses than in many Asian countries because insurance density is high in western industrialized countries.
Tropical cyclones – called “hurricanes” in the Atlantic and “typhoons” in the Pacific – require a seawater surface temperature of 26 to 27 degrees Celsius to form. “In the North Atlantic we have had record high temperatures one to two degrees above the average from 1982 to 2011 for almost a year and a half,” said Rädler. As the meteorologist explains, comparatively cool water temperatures in the western Pacific are also a factor that can promote the formation of hurricanes. The western Pacific experiences alternating periods of warmer and cooler water temperatures, the former known as “El Niño” and the latter as “La Niña”.
Climate expert: Slipping in the Pacific in La Niña situation
“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 slipping 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 does not automatically mean catastrophic devastation. “A severe storm can cause serious damage even in a relatively 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, things could be comparatively calm in the Pacific this summer with fewer typhoons than usual.
Source: Stern
