Fig. 1: Observed and simulated extreme atmospheric rivers (EARs).

Normalized accumulated EAR integrated water vapor transport (IVT, kg/m/s) in boreal winter season (ONDJFM) in ERA5 reanalysis (a the fifth generation European Center for Medium-Range Weather Forecasts atmospheric reanalysis²⁵), HR-CESM (c High Resolution Community Earth System Model) and LR-CMIP6 (e Low Resolution Coupled Model Intercomparison Project Phase 6) during 1979–2005. b, d, as for a, c, but for precipitation (mm/day). EAR IVT (kg/m/s) averaged in AR-active regions (red boxes outlined in Fig. 2d) for ERA5 reanlysis, HR-CESM and LR-CMIP6 during 1979–2005 (f). Calculation details of EAR IVT and precipitation are given in Methods. Source data are provided as a Source Data file.