Climate change increases total and extreme precipitation across the northeastern United States

Keywords: Extreme precipitation, Northeast, climate change
Session Type: Virtual Paper
Day: Saturday
Session Start / End Time: 4/10/2021 08:00 AM (Pacific Time (US & Canada)) - 4/10/2021 09:15 AM (Pacific Time (US & Canada))
Room: Virtual 40

Abstract

Over the past 25 years, total and extreme precipitation have increased dramatically across the northeastern United States. While the recent increase in precipitation is clear, whether enhanced Northeast precipitation will continue into the future or be exacerbated by climate change, is not. To address this question of critical importance to climate change adaptation in the Northeast, we analyzed historical (1976-2005) and future (2070-2099) total and extreme precipitation from West Virginia to Maine using the Weather Research and Forecasting (WRF) regional climate model forced with the National Center for Atmospheric Research Community Earth System Model.

To build confidence in the ability of WRF to model precipitation over the Northeast, we use Daymet, a gridded observational data set, to assess the accuracy of our simulations. Compared to Daymet, WRF has a slight dry bias of approximately 4% for annual total precipitation and a 10% wet bias for annual extreme precipitation. We then examined future precipitation, finding that total annual and extreme precipitation in the Northeast will increase by 11% and 56%, respectively, by the end of the century. Increases in extreme precipitation are primarily driven by more frequent extreme events, with some enhanced intensity. We further assess the seasonality and possible atmospheric drivers of changes in total extreme precipitation.