Researchers warn that warming ocean hot spots are fueling more intense hurricanes and typhoons beyond Category 5. These deep-heat regions, expanding due to climate change, have led to over half of the strongest storms occurring in the past decade. Experts call for a new classification to better inform public preparedness.
Ocean regions harboring deep layers of warm water are intensifying the world's most powerful tropical cyclones, according to new findings presented by I-I Lin, a chair professor at National Taiwan University. Speaking at the American Geophysical Union's 2025 Annual Meeting in New Orleans, Louisiana, Lin highlighted how these hot spots in the North Atlantic and Western Pacific are growing, with human-caused climate change accounting for 60-70% of the expansion.
Lin's research builds on her decade-long study of extreme storms, spurred by Typhoon Haiyan's devastating strike on the Philippines in November 2013, which killed thousands. In a 2014 paper in Geophysical Research Letters, she and colleagues proposed a Category 6 for storms with winds exceeding 160 knots, surpassing the current Category 5 threshold of 137 knots. This would align with the roughly 20-knot ranges in other categories, such as Category 4's 114-137 knots.
Historical records show 18 such super-storms over the past 40 years, with eight from 1982 to 2011 and ten from 2013 to 2023—more than half in the recent decade. Notable examples include Hurricane Wilma in 2005, the strongest in the Atlantic; Typhoon Haiyan; Typhoon Hagibis, which battered Tokyo in 2019; and Hurricane Patricia off Mexico, reaching 185 knots. "Patricia was the king of the world," Lin remarked.
These hot spots, one east of the Philippines and Borneo in the Western Pacific and another near Cuba, Hispaniola, and Florida in the North Atlantic, feature warm water extending deep enough to sustain storm strength despite upwelling. The Atlantic hot spot has spread eastward beyond South America's northern coast and westward into the Gulf, while the Pacific one has also enlarged. However, Lin stressed, "The hot spots are a necessary but not sufficient condition," as atmospheric factors must align.
Formalizing Category 6 could enhance disaster planning in vulnerable areas. "We really think there is a need just to provide the public with more important information," Lin said, urging better awareness of these off-the-charts threats.
