Rising Intensity of Supercharged Hurricanes Sparks Demand for Cat 6 Classification
Scientists warn that warming sea surface temperatures are fueling a surge of extreme, off-the-charts storms, prompting a new hurricane category.
Recent research from the American Geophysical Union reveals that warm, deep ocean hot spots are leading to stronger and more dangerous hurricanes and typhoons. These regions, particularly near the Philippines and the Caribbean, are expanding as climate change warms ocean waters far below the surface, resulting in storms that can exceed Category 5 in the North Atlantic and Western Pacific.
The changes are driven not only by warmer surface waters but also by heat that extends deep into the ocean. New findings suggest that human-caused climate change may account for as much as 70 percent of the expansion of these storm-forming hot spots.
As these hot spots grow, they increase the likelihood of exceptionally intense tropical cyclones, sometimes referred to as Category ‘6’ storms, making landfall near heavily populated coastlines. Researchers believe that recognizing a new Category ‘6’ could enhance public awareness and improve disaster planning.
I-I Lin, a chair professor in the Department of Atmospheric Science at the National Taiwan University, presented this research during an oral session focused on tropical cyclones at AGU’s 2025 Annual Meeting in New Orleans, Louisiana.
Why Scientists Are Calling for a New Storm Category
Lin has dedicated over a decade to studying the most extreme hurricanes and typhoons. Her work gained urgency following Typhoon Haiyan, also known as Super Typhoon Yolanda, which struck the Philippines in November 2013, resulting in thousands of fatalities.
In 2014, Lin and her colleagues published research in the AGU journal Geophysical Research Letters, advocating for a new classification: Category 6. Under their proposal, Category 6 tropical cyclones would include storms with wind speeds exceeding 160 knots. Until now, any storm stronger than 137 knots has been classified as Category 5, which remains the highest level recognized by most weather agencies.
Lin pointed out that most hurricane categories span a range of about 20 knots, making a separate Category 6 more consistent with existing classifications. For instance, Category 4 includes winds between 114-137 knots.
The Strongest Storms on Record
Several notable storms would qualify for this proposed Category 6. Hurricane Wilma, which occurred in 2005, remains the most intense hurricane ever recorded in the Atlantic basin. Typhoon Haiyan also meets the criteria, as does Typhoon Hagibis, which struck Tokyo in 2019, causing extensive damage despite weakening before landfall.
Another significant example is Hurricane Patricia, which formed in the Pacific Ocean off Mexico’s coast. Patricia holds the record as the strongest tropical cyclone ever observed, with winds reaching up to 185 knots—powerful enough to qualify as a Category 7 storm if such a category existed. Lin remarked, “Patricia was the king of the world.”
Burgeoning Ocean Hotspots Feed Big Storms
To assess the frequency of these extreme storms, Lin and her team analyzed records of major tropical cyclones over the past 40 years. Their findings indicate that storms exceeding 160 knots are becoming more common. Between 1982 and 2011, only eight such storms were recorded, while from 2013 to 2023, that number increased to ten.
In total, 18 Category ‘6’ storms have occurred over the last four decades, with more than half forming in just the most recent decade.
Where the Most Dangerous Storms Are Forming
Lin’s ongoing research shows that nearly all Category ‘6’ tropical cyclones develop within specific ocean hot spots. The largest of these is located in the Western Pacific, east of the Philippines and Borneo. Another significant hot spot stretches across parts of the North Atlantic near Cuba, Hispaniola, and Florida.
The study also found that these hot spots are expanding. In the North Atlantic, the region has spread eastward beyond the northern coast of South America and westward into much of the Gulf. The Western Pacific hot spot has also increased in size.
Why Deep Ocean Heat Makes Storms Stronger
The defining feature of these hot spots is not just warm surface water but also unusually deep layers of heat beneath the surface. In many ocean areas, strong storms stir up cooler water from below, which can weaken them. However, in hot spot regions, warm water extends so deep that storms do not cool as easily.
Lin emphasized that warm ocean conditions alone do not guarantee the formation of a Category ‘6’ storm; atmospheric conditions must also align. “The hot spots are a necessary but not sufficient condition,” she stated.
Climate Change Plays a Major Role
The researchers found that both natural temperature cycles and long-term warming contribute to deep ocean hot spots. Their analysis suggests that human-caused climate change is responsible for roughly 60-70 percent of the growth of these hot spots, which in turn increases the likelihood of Category ‘6’ tropical cyclones.
Lin believes that formally recognizing Category ‘6’ storms could help governments and communities better prepare for future impacts, especially in regions where these extreme systems are becoming more common. “We really think there is a need just to provide the public with more important information,” Lin stated.
American Geophysical Union. (2025, December 25). Oceans are supercharging hurricanes past Category 5. ScienceDaily. Retrieved January 8, 2026 from www.sciencedaily.com/releases/2025/12/251225080725.htm
Scientists warn that warming sea surface temperatures are fueling a surge of extreme, off-the-charts storms, prompting a new hurricane category.
Recent research from the American Geophysical Union reveals that warm, deep ocean hot spots are leading to stronger and more dangerous hurricanes and typhoons. These regions, particularly near the Philippines and the Caribbean, are expanding as climate change warms ocean waters far below the surface, resulting in storms that can exceed Category 5 in the North Atlantic and Western Pacific.
The changes are driven not only by warmer surface waters but also by heat that extends deep into the ocean. New findings suggest that human-caused climate change may account for as much as 70 percent of the expansion of these storm-forming hot spots.
As these hot spots grow, they increase the likelihood of exceptionally intense tropical cyclones, sometimes referred to as Category ‘6’ storms, making landfall near heavily populated coastlines. Researchers believe that recognizing a new Category ‘6’ could enhance public awareness and improve disaster planning.
I-I Lin, a chair professor in the Department of Atmospheric Science at the National Taiwan University, presented this research during an oral session focused on tropical cyclones at AGU’s 2025 Annual Meeting in New Orleans, Louisiana.
Why Scientists Are Calling for a New Storm Category
Lin has dedicated over a decade to studying the most extreme hurricanes and typhoons. Her work gained urgency following Typhoon Haiyan, also known as Super Typhoon Yolanda, which struck the Philippines in November 2013, resulting in thousands of fatalities.
In 2014, Lin and her colleagues published research in the AGU journal Geophysical Research Letters, advocating for a new classification: Category 6. Under their proposal, Category 6 tropical cyclones would include storms with wind speeds exceeding 160 knots. Until now, any storm stronger than 137 knots has been classified as Category 5, which remains the highest level recognized by most weather agencies.
Lin pointed out that most hurricane categories span a range of about 20 knots, making a separate Category 6 more consistent with existing classifications. For instance, Category 4 includes winds between 114-137 knots.
The Strongest Storms on Record
Several notable storms would qualify for this proposed Category 6. Hurricane Wilma, which occurred in 2005, remains the most intense hurricane ever recorded in the Atlantic basin. Typhoon Haiyan also meets the criteria, as does Typhoon Hagibis, which struck Tokyo in 2019, causing extensive damage despite weakening before landfall.
Another significant example is Hurricane Patricia, which formed in the Pacific Ocean off Mexico’s coast. Patricia holds the record as the strongest tropical cyclone ever observed, with winds reaching up to 185 knots—powerful enough to qualify as a Category 7 storm if such a category existed. Lin remarked, “Patricia was the king of the world.”
Burgeoning Ocean Hotspots Feed Big Storms
To assess the frequency of these extreme storms, Lin and her team analyzed records of major tropical cyclones over the past 40 years. Their findings indicate that storms exceeding 160 knots are becoming more common. Between 1982 and 2011, only eight such storms were recorded, while from 2013 to 2023, that number increased to ten.
In total, 18 Category ‘6’ storms have occurred over the last four decades, with more than half forming in just the most recent decade.
Where the Most Dangerous Storms Are Forming
Lin’s ongoing research shows that nearly all Category ‘6’ tropical cyclones develop within specific ocean hot spots. The largest of these is located in the Western Pacific, east of the Philippines and Borneo. Another significant hot spot stretches across parts of the North Atlantic near Cuba, Hispaniola, and Florida.
The study also found that these hot spots are expanding. In the North Atlantic, the region has spread eastward beyond the northern coast of South America and westward into much of the Gulf. The Western Pacific hot spot has also increased in size.
Why Deep Ocean Heat Makes Storms Stronger
The defining feature of these hot spots is not just warm surface water but also unusually deep layers of heat beneath the surface. In many ocean areas, strong storms stir up cooler water from below, which can weaken them. However, in hot spot regions, warm water extends so deep that storms do not cool as easily.
Lin emphasized that warm ocean conditions alone do not guarantee the formation of a Category ‘6’ storm; atmospheric conditions must also align. “The hot spots are a necessary but not sufficient condition,” she stated.
Climate Change Plays a Major Role
The researchers found that both natural temperature cycles and long-term warming contribute to deep ocean hot spots. Their analysis suggests that human-caused climate change is responsible for roughly 60-70 percent of the growth of these hot spots, which in turn increases the likelihood of Category ‘6’ tropical cyclones.
Lin believes that formally recognizing Category ‘6’ storms could help governments and communities better prepare for future impacts, especially in regions where these extreme systems are becoming more common. “We really think there is a need just to provide the public with more important information,” Lin stated.
American Geophysical Union. (2025, December 25). Oceans are supercharging hurricanes past Category 5. ScienceDaily. Retrieved January 8, 2026 from www.sciencedaily.com/releases/2025/12/251225080725.htm
