Distributions of Short‐Duration High‐Intensity Precipitation Events in the United States Under Intermediate and Pessimistic Climate Change Scenarios

Abstract Under a warming climate, the magnitude and frequency of intense precipitation are expected to increase globally, on average. However, changes in the regional variability of short‐duration high‐intensity (SDHI) precipitation across the contiguous United States—both temporally and spatially—remain uncertain, and most projections rest on resolutions too coarse to resolve the responsible processes. Herein, convection‐permitting, dynamically downscaled simulation output at 3.75 km grid spacing and 15‐min intervals is used to examine potential changes in the occurrence, accumulation, and magnitude of sub‐daily precipitation relative to simulated historical levels. Changes are concentrated at both tails of the intensity distribution: precipitation at or above the percentile increases significantly in five of seven regions, exceeding 100% in the Northwest, while lighter intensities decrease by 10%–40%. These changes are regionally and seasonally concentrated rather than uniform, and their dependence on accumulation duration varies by region, so future hydroclimates may be characterized by fewer light‐to‐moderate events punctuated by more intense ones, a redistribution that will challenge water management and infrastructure design.