Cyclones

Tropical Storm Debby was moving so slowly, Olympians could have outrun it as it moved across the Southeast in early August 2024. That gave its rainfall time to deluge cities and farms over large parts of Florida, Georgia and the Carolinas. More than a foot of rain had fallen in some areas by early Aug. 7, 2024, with more days of rain forecast there and into the Northeast. Mathew Barlow, a climate scientist at UMass Lowell, explains how storms like Debby pick up so much moisture, what can cause them to slow or stall, and what climate change has to do with it. What causes hurricanes to stall? Hurricanes are steered by the weather systems they interact with, including other storms moving across the U.S. and the Bermuda High over the Atlantic Ocean. A hurricane may be moving slowly because there are no weather systems close enough to pull the hurricane along, or there might be a high-pressure system to the north of the hurricane that blocks its forward movement. In this case,...

Tropical Storm Debby was moving so slowly, Olympians could have outrun it as it moved across the Southeast in early August 2024. That gave its rainfall time to deluge cities and farms over large parts of Florida, Georgia and the Carolinas. More than a foot of rain had fallen in some areas by early Aug. 7, 2024, with more days of rain forecast there and into the Northeast. Mathew Barlow, a climate scientist at UMass Lowell, explains how storms like Debby pick up so much moisture, what can cause them to slow or stall, and what climate change has to do with it. What causes hurricanes to stall? Hurricanes are steered by the weather systems they interact with, including other storms moving across the U.S. and the Bermuda High over the Atlantic Ocean. A hurricane may be moving slowly because there are no weather systems close enough to pull the hurricane along, or there might be a high-pressure system to the north of the hurricane that blocks its forward movement. In this case,...

Tropical cyclones have been growing stronger worldwide over the past 30 years, and not just the big ones that you hear about. Our new research finds that weak tropical cyclones have gotten at least 15% more intense in ocean basins where they occur around the world. That means storms that might have caused minimal damage a few decades ago are growing more dangerous as the planet warms. Warmer oceans provide more energy for storms to intensify, and theory and climate models point to powerful storms growing stronger, but intensity isn’t easy to document. We found a way to measure intensity by using the ocean currents beneath the storms – with the help of thousands of floating beachball-sized labs called drifters that beam back measurements from around the world. Why it’s been tough to measure intensity Tropical cyclones are large storms with rotating winds and clouds that form over warm ocean water. They are known as tropical storms or hurricanes in the Atlantic...