Nav: Home

What is causing more extreme precipitation in the northeast?

July 31, 2018

From Maine to West Virginia, the Northeast has seen a larger increase in extreme precipitation than anywhere else in the U.S. Prior research found that these heavy rain and snow events, defined as a day with about two inches of precipitation or more, have been 53 percent higher in the Northeast since 1996. A Dartmouth study finds that hurricanes and tropical storms are the primary cause of this increase, followed by thunderstorms along fronts and extratropical cyclones like Nor'easters. The findings are published in the Journal of Geophysical Research.

"Our study provides insight into what types of extreme storms are changing and why. We found that hurricanes were responsible for nearly half of the increase in extreme rainfall across the Northeast. A warmer Atlantic Ocean and more water vapor in the atmosphere are fueling these storms, causing them to drop more rain over the Northeast," explains Jonathan M. Winter, an assistant professor of geography at Dartmouth and co-author of the study. "Other research has demonstrated that these two conditions have been enhanced in our warmer world," added Huanping Huang, a graduate student in earth sciences at Dartmouth and the study's lead author.

The findings demonstrate that 88 percent of the extreme precipitation increase after 1996 was caused by large storms in Feb., March, June, July, Sept. and Oct.
  • Hurricanes and tropical storms, also known as "tropical cyclones," accounted for nearly half, or 48 percent, of the increase in extreme rainfall. After 1996, the Northeast experienced almost four times more extreme rainfall events from hurricanes and tropical storms than from 1979-1995.

  • Severe thunderstorms along "fronts," especially intense downpours along cold fronts, accounted for 25 percent of the increase in extreme precipitation.

  • Nor'easters and other "extratropical cyclones," which are storms that form outside of the tropics, accounted for 15 percent of the increase in extreme precipitation.

  • Other research has found that the causes of more frequent extreme precipitation events in this study -- increased ocean temperatures, more water vapor in the atmosphere, and a wavier jet stream -- are associated with a warmer world.


These results build on the team's earlier research by examining what caused the increase in heavier or extreme precipitation beginning in 1996. The researchers analyzed precipitation data from 1979 to 2016 across the Northeast-- Maine, New Hampshire, Vermont, Mass., Conn., R.I., N.J., N.Y., Pa., Md., DC, Del., and W.Va. in conjunction with data pertaining to daily weather maps and oceanic and atmospheric fields.
-end-
Winter is available for comment at: Jonathan.M.Winter@dartmouth.edu. Huanping Huang and Erich C. Osterberg in earth sciences at Dartmouth also served as co-authors of the study.

Dartmouth College

Related Hurricanes Articles:

Earthquakes, hurricanes and other natural disasters obey same mathematical pattern
Researchers from the Centre for Mathematical Research (CRM) and the Universitat Autònoma de Barcelona have mathematically described the frequency of several dangerous phenomena according to their size with more precision than ever.
Cold, dry planets could have a lot of hurricanes
Study overturns conventional wisdom that water is needed to create cyclones.
Climate simulations project wetter, windier hurricanes
New supercomputer simulations by climate scientists at Lawrence Berkeley National Laboratory have shown that climate change intensified the amount of rainfall in recent hurricanes such as Katrina, Irma, and Maria by 5 to 10 percent.
More category 5 hurricanes forecasted by scientists
Researchers at Chapman University have learned from studying 2012's Hurricane Sandy, that we are more likely to see larger, more powerful hurricanes in the future.
Hurricanes are slowing down, and that's bad news
Some hurricanes are moving more slowly, spending increased time over land and leading to catastrophic local rainfall and flooding, according to a new study published Wednesday (June 6) in the journal Nature.
More Hurricanes News and Hurricanes Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...