Hurricane Harvey lingered over south Texas for more than a week last September, dumping up to 60 inches of rain that left most of Houston underwater and resulted in 93 deaths.
The U.S. National Hurricane Center said Tropical Storm Aletta was centered about 350 miles (565 kilometers) south-southwest of Manzanillo, Mexico, Wednesday morning.
By plugging storm data into computer models representing a future with temperatures that are up to five degrees warmer, they found that these cyclones moved 9 percent slower and were far, far wetter.
In the last 70 years the storms have slowed by ten per cent.
Dr Kossin said: 'Tropical cyclones over land have slowed down 20 per cent in the Atlantic, 30 per cent in the western North Pacific, and 19 per cent in the Australian region.
The center said the storm was likely to strengthen some more as it moved farther out into the Pacific, but predicted Aletta would begin weakening Saturday.
These two trends ought to work in tandem to make today's storms much worse rainmakers. "The storms will stay in your neighborhoods longer".
James Kossin's research showed that over the past 68 years, cyclones have slowed by 10 percent globally as the planet warms.
Although commending the study for its findings, she said it is not without its limitations. Given that storms in some regions are migrating poleward and already increasing in intensity, cyclones delivering unusually powerful bouts of rain may threaten places not normally in their path.
Kossin would actually agree on that point. A slow storm increases the risk of damaging floods. Rainfall, on average, increased 24 percent.
Dr Kossin said more rain was also falling during cyclones, and there was evidence that tropical cyclones were migrating more towards the poles. The fact that their results show quite similar trends should be a wake-up call.