According to a new study by Dartmouth, the Northeast is expected to experience a 52% increase in extreme precipitation events by the end of the century due to a warmer climate creating more humid conditions. Extreme precipitation events are defined as 1.5 inches or more of heavy rainfall or melted snowfall in a day.

Christopher J. Picard ’23, an earth sciences major and undergraduate researcher in the Applied Hydroclimatology Group at Dartmouth, explained:

“As climate change brings warmer temperatures, you have more water vapor in the atmosphere, which creates the right conditions for extreme precipitation.”

“Our findings show that this increase in extreme precipitation will be primarily driven by more frequent heavy rainfall events, not by the intensity of such events. In other words, we expect a large increase in the number of extreme precipitation days, and a smaller increase in the amount of rain on each extreme precipitation day.”

The study indicates that extreme precipitation in the region will increase by 52% by the end of the century. Winter and spring will contribute the most to this increase, with a 109% and 89% increase respectively.

Jonathan Winter, an associate professor of geography and lead of the Applied Hydroclimatology Group at Dartmouth, and his team analyzed historical data from 1901 to 2014 to understand changes in heavy rainfall events in the Northeast. They found a 50% increase in extreme precipitation from 1996 to 2014, which was linked to climate change. You can learn more about this research through the link to the article.

Winter said,

“Building on our earlier work, we were particularly interested in determining how much extreme precipitation is expected to change across the Northeast in the future.”

The new study defines the Northeast as Maine, New Hampshire, Vermont, Massachusetts, Connecticut, Rhode Island, New Jersey, New York, Pennsylvania, Maryland, Delaware, West Virginia, and Washington, D.C., just like their other papers.

Northeast extreme precipitation change prediction

Dartmouth’s study found that the largest projected increases in extreme precipitation are in West Virginia, parts of Pennsylvania, central New York, and northeastern Maine. Predominantly smaller increases are expected along the Atlantic coast and south of Lake Ontario.

The researchers used a regional climate model from the National Center for Atmosphere Research to simulate precipitation for a historical period of 1996 to 2005 and future period of 2070 to 2099. They then compared their results to simulations of changing heavy rainfall events from other regional climate models. They found that their results are consistent with the other regional climate model simulations, which predict increases in extreme precipitation ranging from 58% to 169%.

Image Credits

In-Article Image Credits

Northeast extreme precipitation change prediction via Applied Hydroclimatology Group at Dartmouth with usage type - News Release Media
Hard rain on a roof via Wikimedia Commons by W. Carter with usage type - Creative Commons License. June 11, 2018