Shift Toward Intense and Widespread Precipitation Events Over the United States by Mid‐21st Century

Abstract

The United States has witnessed an increase in the frequency of intense and spatially widespread precipitation events in recent decades. Using a high-resolution hybrid ensemble of regional climate simulations, we project further intensification of widespread extremes in the near future. The simulations cover 1966-2005 in the historical period and 2011-2050 in the future period under RCP8.5 scenario and show good correspondence with the observations in the historical period. The projected changes in the characteristics of precipitation events are associated with more frequent occurrence of extreme years where contribution from intense and widespread events to the annual precipitation is unprecedently high. While our findings are consistent with recent trends in the observations, they are in contrast to some earlier studies that project shrinking of precipitation events in the future period, which highlight the need for more rigorous investigations of changes in the spatial extent of precipitation in future climates.

A Vine Copula‐Based Ensemble Projection of Precipitation Intensity–Duration–Frequency Curves at Sub‐Daily to Multi‐Day Time Scales

“…The intense and widespread heavy rainfall events were not considered in the future projections of IDF curves. Previous studies have shown that the spatial dependence of precipitation could increase under a warming climate, leading to more intense and widespread heavy rainfall events (Rastogi et al, 2020). It is thus desired to consider possible changes in the spatial dependence between IDF curves in future studies (see Figure S4 in Supporting Information S1).…”

Projected Changes in Temperature and Precipitation Over the United States, Central America, and the Caribbean in CMIP6 GCMs

“…For instance, there has been a decreasing trend in snow accumulation in the western United States (U.S.) during the cold season over the last several decades (Mote et al 2005;Ashfaq et al 2013). Similarly, several regions are experiencing increasing trends in minimum temperatures (Batibeniz et al 2020) and more intense and widespread precipitation extremes (Rastogi et al 2020). Mean temperatures are also increasing in southwestern U.S. and northwestern Mexico (Cavazos et al 2020).…”

Climate change increases risk of extreme rainfall following wildfire in the western United States

“…Simultaneously, significant increases in the magnitude and frequency of extreme precipitation are projected for the early 21st century in much of the western United States ( 21 ), and by mid-century, the frequency and rainfall volume of mid-sized heavy precipitation events are expected to increase by more than 30% ( 22 ). These effects are particularly pronounced in California: During the most extreme atmospheric river-driven events, California is projected to receive ~25% more precipitation—with maximum precipitation rates during these events potentially increasing by 50% or more in some areas ( 23 ), along with an increasing fraction of precipitation falling as rain rather than snow ( 24 ).…”