Extreme precipitation change between 2070–2099 and 1996–2005. Credit: C.Picard et al.
Key points:
- A new study projects precipitation to increase in the northeast by 52%.
- The findings show that winter and spring contribute most to the projected increase.
- Extreme precipitation will be primarily driven by more frequent heavy rainfall events, not by the intensity of such events.
The warming climate and humid conditions in the Northeast are expected to bring about extreme precipitation events, including heavy rains and melting snow. According to a new Dartmouth study, both are projected to increase in the northeast by 52% by the end of the century.
Previous research by the team showed there was a climate change-linked 50% increase in extreme precipitation from 1996 to 2014. Building on that, the researchers applied 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. Then, they compared their results to simulations of changing heavy rainfall events from other regional climate models.
The results, published in Climatic Change, are consistent with other regional climate model simulations that predict increases in extreme precipitation ranging from 58% to 169%. The findings show that winter and spring contribute most to the projected 52% increase in the northeast region from 2070 to 2099. For the purposes of the study, the northeast is defined as Maine, New Hampshire, Vermont, Massachusetts, Connecticut, Rhode Island, New Jersey, New York, Pennsylvania, Maryland, Delaware, West Virginia, and Washington, D.C.
"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," said first author Christopher J. Picard, an earth sciences major and undergraduate researcher 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."
The study also found that extreme precipitation increases are projected to be largest in West Virginia, parts of Pennsylvania, central New York and northeastern Maine.