Most assessments of hurricanes under climate change focus on wind speed. Research from Newcastle University's School of Engineering, involving Professor of Climate Change Impacts Hayley Fowler, shifts attention to size, speed and rain. Using satellite observations of North Atlantic tropical cyclones from 2001 to 2024, and a dynamic definition of storm size that evolves over each storm's lifetime, the team quantified how storms respond to warmer conditions.
The findings, in npj Climate and Atmospheric Science, show storm precipitation increasing by around 21 percent for each degree rise in local dewpoint temperature, with the area of heavy rainfall expanding by about 12.5 percent per degree. Storms generally shrink slightly as temperatures rise, but that relationship reverses over very warm waters, especially the Caribbean, where storms can instead grow larger, move more slowly and persist for longer.
That combination, bigger storms crawling over saturated ground, is precisely the recipe for catastrophic flooding of the kind recent hurricanes have delivered. The work implies that risk models calibrated to historical storm footprints and speeds will underestimate future rainfall hazard in the Caribbean and along warm coastlines, with consequences for infrastructure design, insurance and emergency planning throughout the basin.