This summer, in particular, has been characterized by intense rainfall and floods. States such as Texas, New Mexico, North Carolina, Illinois, New York and New Jersey are among those that experienced major flooding events in recent weeks. Earlier this month, the country was hit by at least four 1-in-1,000-year rainfall events in less than a week.
In June, flash floods killed at least nine people in West Virginia after around 2.5 to 4 inches of rain fell over parts of Ohio County in only 30 minutes.
At least 120 people were killed in central Texas’ Hill Country region in early July after heavy rains caused the Guadalupe River, near Kerrville, to surge more than 20 feet in 90 minutes.
Days later, at least three people were killed by devastating flash floods in the remote village of Ruidoso in New Mexico.
And earlier this week, more than 2 inches of rain fell in a single hour over Central Park in New York City, marking the second-highest one-hour rainfall total recorded in the Big Apple, according to New York City Emergency Management.
The flurry of recent flash floods owes in part to the fact that the summer months tend to be some of the stormiest of the year, said Russ Schumacher, director of the Colorado Climate Center at Colorado State University and the state climatologist.
“June through October is when you can get really heavy rainfall in parts of the country,” he said, adding that the Atlantic hurricane season also runs from June 1 to Nov. 30, which can dump rain along the Atlantic and Gulf coasts.
But studies have shown that climate change is expected to make storms more frequent and intense, which increases the risk of heavy rainfall and flooding.
“A warmer atmosphere has more water vapor in it that can then be rained out,” Schumacher said. “The evidence for that is quite strong.”
Still, part of the reason why there are more warnings issued than ever before is because scientists are able to detect and track weather systems in greater detail now.
Radar systems and weather models have significantly improved over the course of 40 years, which contributes to the number of warnings issued during extreme weather events, said Amir AghaKouchak, director of the Center for Hydrometeorology and Remote Sensing at the University of California, Irvine.
“The system that was implemented back in the ‘80s is not the same as the system that we have now,” he said. “We have many, many more radars, and we have many different sources of data. So naturally you expect more warnings just because our systems are getting better and better.”
These warnings are essential for saving lives, but they are also crucial to protect infrastructure such as dams, levees or drainage systems that are vulnerable during flooding events, AghaKouchak said.
“It’s all a reminder that these events can be major catastrophes,” he said. “The Texas flood was a huge disaster, and so we always have to be prepared.”
