How El Niño and Climate Change Supercharged This Week's East Coast Storm

The winter storm that raked the East Coast this week, flooding coastal communities from Florida to Maine and killing at least five people, was likely made more intense by climate change and El Niño, meteorologists said.

"The rainfall events we had from this storm were off the charts in some places, and that's a reflection of the warming climate," meteorologist Jeff Masters told Newsweek. Masters, a former hurricane hunter with the National Oceanic and Atmospheric Administration and co-founder of the site Weather Underground, writes about climate change and extreme weather for Yale Climate Connections.

Masters said this week's downpours in New England are part of a longer climate-related increase in heavy rainfall events. He pointed out the dramatic jump in days with heavy precipitation in the Northeast over the past 60 years coinciding with a warmer climate that holds more moisture.

"If you look at the 5-plus-inch rainfall events, those doubled over the last few decades," Masters said. "So, we're seeing an intensification of very heavy rainfall events."

The Fifth National Climate Assessment, published last month by the U.S. Global Change Research Program, shows a 103 percent increase in those very heavy rainfall days in the Northeast since 1958. Overall, heavy rainfall days of at least 2 inches in the Northeast grew by 60 percent since midcentury, and by 37 percent in the Southeast.

December storms are natural events, Masters said, but the warmer atmosphere and higher-than-average sea temperatures took this storm to extremes.

"It was a record extreme as far as setting low pressure records for the eastern U.S. for December," Masters said. "We've never seen a storm this intense as far as low pressure goes this time of year."

Masters said the storm also caused coastal surge flooding on par with what might be expected from a major hurricane in some places, including Charleston, South Carolina, and Tampa, Florida.

Jeff Berardelli monitored the storm from Tampa, where he is chief meteorologist and climate specialist at television station WFLA.

Berardelli said the cyclical atmospheric event known as El Niño likely had a big influence on the storm.

"El Niño is juicing the Earth system with extra heat," he told Newsweek in an email exchange. This storm was fed by warmer-than-average waters from both the Caribbean and the Gulf Stream current, he said, and the coastal effects were likely made worse by sea level rise and climate change.

"Climate change is the shot of steroids, giving it a boost," Berardelli said. "Low-lying cities will need to start making adaptations soon."

Masters echoed that sentiment and said this week's storm is more evidence that coastal communities should be preparing for a warmer, wetter world.

"We need to be prepared for the climate of the 21st century, and our infrastructure is designed for the climate of the 20th century," he said.