A new study finds that tropical cyclones around the world are moving slightly slower over land and water, dumping more rain as they stall, just as Hurricane Harvey did previous year.
The U.S. National Hurricane Center said Aletta, which had become a tropical storm late Wednesday, was centered about 455 miles west-southwest of Manzanillo, Mexico, and had maximum sustained winds of 75 mph.
And that was before slowpoke Harvey hit past year. The change is even more dramatic in storms that have made landfall from the North Atlantic - they're moving 20 percent slower. To help, the Texas General Land Office partnered up with the University of Texas to conduct a survey for Texans who live in the affected areas, asking if they are still displaced and how much damage to their homes still need to be fixed.
Study author James Kossin of the National Oceanic and Atmospheric Administration says Harvey is a great example of what he found.
Kossin published his findings Wednesday in the journal Nature.
Kossin's work was based on details of nearly 70 years' worth of storms, but he made no attempt to determine what was causing the slowdown. "The storms will stay in your neighborhoods longer". He showed that from 1949 to 2016, tropical cyclones across the globe slowed their movement by 10 percent on average.
Although commending the study for its findings, she said it is not without its limitations.
Kossin would actually agree on that point.
"These trends are nearly certainly increasing local rainfall totals and freshwater flooding, which is associated with very high mortality risk", he said. The storms, in effect, are sticking around places for a longer period of time. "That has serious implications for inland flooding and urban infrastructure".
"I went in with that hypothesis and looked at the data, and out popped the signal that was much bigger than anything I was expecting", Kossin said. And there are limits to each approach.
"We're both pushing the work forward and adding additional lines of evidence", Gutmann says. "And, unfortunately, this signal would point to more freshwater flooding".