Projected Changes in Wind Hazards From Extreme Extratropical Cyclones in the Northeastern U.S.

Abstract Extratropical Cyclones (ETCs) can produce high‐impact weather in mid‐latitudes, leading to extreme precipitation, winds, and storm surges. Despite the societal and economic impacts of ETCs, gaps remain in our understanding of how ETCs and their related hazards will change in a changing climate. In this study, we evaluate systematic changes in end‐of‐century ETC characteristics, including intensity, translation speed, and storm size, with a particular focus on evaluating how wind hazards related to ETCs are expected to change under future climate conditions. We leverage the 100‐member Community Earth System Model 2 Large Ensemble (LENS2) data set to identify ETCs that traverse the Northeastern U.S. Results indicate that while the annual frequency of ETCs is projected to decrease under future climate conditions, the minimum pressure decreases and maximum low‐level winds are projected to increase. We also observe track density changes in extreme future ETCs in the Northeast, with more frequent trajectories passing through the Southeastern U.S. and less zonal translation. Additionally, we leverage MPAS's variable‐resolution capabilities to downscale a subset of extreme ETC events from LENS2 to a 3‐km grid over the Northeast. Results highlight a shift toward more intense cyclones, with maximum 10 m and low‐level wind speeds increasing by 28% between present and the end of the century.