Northeast US projected to see a significant increase in extreme precipitation by 2100

A new study from Dartmouth College and posted in the journal Climatic Change predicts that the Northeast United States may have a 52 percent increase in extreme precipitation events by the end of the century.

New York City streets were under feet of water Wednesday night amid a catastrophic flooding event caused by Tropical Rainstorm Ida.

(@BushwickLife via Storyful)

Using regional climate models and studying precipitation data from 1901-2014, the research team, led by senior author Jonathan Winter, an associate professor of geography and lead of the Applied Hydroclimatology Group at Dartmouth, found that there has already been a 50 percent increase in extreme precipitation in the Northeast U.S. between 1996 and 2014, which is mainly due to climate change.

As the region warms, the atmosphere is able to hold more water vapor, which in turn is expected to create more extreme precipitation events through the end of the century.

An extreme precipitation event is defined in this study as 1.5 inches of more of rain/melted snow in one day.

The researchers also noted that the increase in extreme precipitation will be mostly due to a higher frequency of extreme events rather than an uptick in intensity.

The greatest increase in extreme precipitation is projected over parts of West Virginia, Pennsylvania, central New York and northeastern Maine. The lowest increase is expected along the Atlantic coast, where a majority of the population lives.

The winter season is expected to have the highest increase (109%) in extreme rain and snow events by the end of the century followed by spring (89%).

Key excerpt from the EurekAlert story........

"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," says first author Christopher J. Picard '23, an earth sciences major and undergraduate researcher in the Applied Hydroclimatology Group at Dartmouth. "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."