Tropical Systems Causing More Extreme Precipitation in the Northeast

news image
Special Stories
6 Aug 2018 8:18 AM
[Image credit: Daliophoto/Flickr] From Dartmouth College 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. Tropical Systems Causing More Extreme Precipitation in the Northeast [Overview of the causal mechanisms of the increase in extreme precipitation in the Northeast since 1996. Graphic provided by Huanping Huang, Jonathan Winter, and Erich Osterberg.] 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.
Tropical Systems Causing More Extreme Precipitation in the Northeast 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 from Maine to West Virginia, in conjunction with data pertaining to daily weather maps and oceanic and atmospheric fields. Edited for WeatherNation by Meteorologist Mace Michaels
All Weather News
More
More Rain for the Soggy Northwest

More Rain for the Soggy Northwest

The Northwestern United States has been hamme

4 Dec 2023 6:40 PM
Record Heat in the Central Plains this Week

Record Heat in the Central Plains this Week

A ridge of high pressure will provide unseaso

4 Dec 2023 6:35 PM
Severe Threat Returns Saturday

Severe Threat Returns Saturday

The risk of severe weather is in the forecast

4 Dec 2023 6:30 PM
More Snow Today in New England

More Snow Today in New England

Heavy snow has hit northern New England with

4 Dec 2023 6:25 PM
Incoming Clipper Systems for the North

Incoming Clipper Systems for the North

A clipper system dropped in from Canada early

4 Dec 2023 4:00 PM
Avalanche Threat & Tough Travel in Colorado

Avalanche Threat & Tough Travel in Colorado

Heavy snow on Vail Pass made for dangerous dr

4 Dec 2023 2:55 PM
Southeast Drier by Monday

Southeast Drier by Monday

As far as rainfall goes, totals have toppled

3 Dec 2023 9:25 PM