Discrepancies in Extreme Daily and Monthly Precipitation Trends Between Observations and Earth System Models

Abstract While extreme precipitation is expected to intensify globally in a warming climate, changes in extreme precipitation on regional scales remain uncertain. To understand how well Earth system models (ESMs) capture recent changes in regional extreme precipitation, we compare trends in daily and monthly extreme precipitation across multiple observational data sets and three ESM ensembles. Observations and ESMs show similar increases in the percent of land area with positive trends in daily precipitation extremes over time, but ESMs underestimate the magnitude of both positive and negative observed trends in daily extremes. For monthly extremes, ESMs simulate much more widespread increases compared to observations in recent decades. As a result, many recent observed decreasing trends in monthly extreme precipitation fall outside the model distribution. We find similar results when comparing observed trends to those in high‐resolution simulations. These results highlight ongoing challenges in constraining the magnitude of regional extreme precipitation change.