To What Extent Are Changes in Flood Magnitude Related to Changes in Precipitation Extremes?

Despite increasing evidence of intensification of extreme precipitation events associated with a warming climate, the magnitude of peak river flows is decreasing in many parts of the world. To better understand the range of relationships between precipitation extremes and floods, we analyzed annual precipitation extremes and flood events over the contiguous United States from 1980 to 2014. A low correlation (less than 0.2) between changes in precipitation extremes and changes in floods was found, attributable to a small fraction of co‐occurrence. The covariation between precipitation extremes and floods is also substantially low, with a majority of catchments having a coefficient of determination of less than 0.5, even among the catchments with a relatively high fraction of annual maxima precipitation that can be linked to floods. The findings indicate a need for more investigations into causal mechanisms driving a nonlinear response of floods to intensified precipitation extremes in a warming climate. Key Points: We assess co‐occurrence and covariation between precipitation extremes and floods to explore the range of their relationshipsThe spatial pattern of changes in precipitation extremes explains less than 20% of the spatial pattern of changes in floodsMost catchments have a covariation of less than 0.5 between annual precipitation extremes and annual floods [ABSTRACT FROM AUTHOR]