The research reported this week in Science Advances points to a specific ocean ingredient that can help determine whether a tropical cyclone is poised to intensify quickly before landfall. The study’s authors focused on marine heat waves—defined as long-lasting, large areas of water in the top 10% of historical heat—and examined how those hotter-than-usual conditions interact with storms after they reach the warm-water “fuel” that helps hurricanes grow. The researchers said the effect is becoming more dangerous as ocean temperatures rise and marine heat waves become more frequent and more concentrated closer to land.
Using tropical cyclone landfall data going back to 1981, the study looked at 1,600 storms in the broader category that includes hurricanes and compared cases in which storms traveled over marine heat waves with cases that did not. The researchers found that when a cyclone crossed extra-hot water, it was more likely to intensify rapidly—a pattern the study linked to a larger jump in the number of disasters meeting a major cost threshold once storms hit land.
The paper’s authors also reported that marine heat waves can matter for a large share of storms at the coast. Gregory Foltz, an oceanographer at the National Oceanic and Atmospheric Administration and a co-author of the study, said in an interview that “These marine heat waves affect more than half of landfalling tropical cyclones,” adding that he expects the conditions to occur “closer to land and more frequently.” Foltz said that makes it important for people to understand that storms encountering those ocean heat conditions are “more likely to result in extreme damages when they make landfall.”
Foltz and other researchers emphasized that this ocean detail could be important for decision-makers because rapid intensification can compress the time available for response. Foltz said meteorologists forecasting storm tracks need to determine whether hurricanes travel over a marine heat wave because it is “more likely to intensify rapidly,” which “can potentially have a bigger impact on landfall.”
The study’s co-author Hamed Moftakhari, a coastal engineering professor at the University of Alabama who studies compound hazards, pointed to recent U.S. hurricane examples in arguing that warm ocean conditions can help drive multiple fast-growing storms. “The story of Helene and Milton is that if you’ve got a warmer ocean, you’ve got the fuel to supercharge tropical cyclones even in a cascade,” Moftakhari said. He added: “So within a few weeks you could get two rapidly intensified hurricanes making landfall in the west coast of Florida,” describing the pattern as “shocking but should also be alarming for people.”
Moftakhari and the study also discussed Hurricane Otis, which rapidly intensified in October 2023 near Acapulco, Mexico. The Associated Press report said the storm intensified from a tropical storm to a Category 5 hurricane in one day, then caused about $16 billion in damage and 52 deaths when it made landfall with 165 mph (265 kph) winds. The study cited Otis as an illustration of how extremely warm ocean conditions can help produce explosive intensification.
Beyond linking marine heat waves to storm behavior, the study’s authors said they tested whether the greater damages were just a side effect of where people build rather than ocean conditions themselves. According to the report, the researchers contrasted storms that crossed hot water and hit developed coasts with other storms that hit similarly urbanized areas but without crossing marine heat waves, and they said the higher damage was not driven by increased coastal development. Soheil Radfar, a scientist who does hurricane hazard modeling at Princeton University and the study’s lead author, said that means the outlook is more dangerous, describing the future as one in which there will be “more rapid intensification, more marine heat waves” and that this will raise the cost for coastlines.
Radfar said the change could be especially challenging for coastal planners and for preparedness over the coming decades. He said the “pieces of the puzzle are going to be really challenging for the coastal environment in the next four decades,” adding that this is expected to cause more billion-dollar disasters. Moftakhari said the work has implications for risk management, including evacuation planning that accounts for storms crossing ocean heat “hot spots” that are more likely to intensify quickly, with earlier triggers for when people should leave. He also said flood-protection designs—such as drainage systems and sea walls—need to be updated to reflect “the new worsening storm reality.”
Outside scientists said the findings align with known hurricane physics and climate change’s role in making warm water persist longer. Brian Tang, a professor of atmospheric sciences at the University at Albany who was not part of the study, said in the report that “Climate change is causing stronger and longer-duration marine heat waves,” explaining that tropical cyclones draw energy and produce heavy rain through evaporation from warm ocean waters. Tang said it is “reasonable that marine heat waves are turbocharging hurricanes,” and described the phenomenon as “In effect, the dice is being loaded.”
When hurricanes and marine heat waves intersect, the study suggests, the ocean can meaningfully shift the odds of rapid intensification and therefore the severity of landfall impacts.