Impact of deep-inland typhoon track uncertainty on the 2023 record-breaking rainfall over North China: an ensemble-based analysis

Abstract Extreme rainfall associated with typhoons remains a persistent forecasting challenge, particularly in regions influenced by complex multiscale interactions. Although typhoon-induced precipitation has been extensively studied, the influence of forecast uncertainty on inland rainfall—particularly over complex terrain—remains insufficiently understood. In this study, we applied ensemble sensitivity analysis to European Centre for Medium-Range Weather Forecasts ensemble to diagnose large-scale circulation controls on the unprecedented Beijing–Tianjin–Hebei rainfall event from 29 July to 1 August 2023, driven by the remnants of Typhoon Doksuri. Results showed that rainfall extremes are tightly governed by the trajectory of the remnants of typhoon cyclonic circulation, which modulates the spatial alignment among moisture flux, typhoon intensity, and terrain-enhanced convergence. Deviations from the observed track—either eastward or westward—disrupt this spatial alignment, leading to substantially reduced precipitation despite comparable or stronger moisture flux. These findings improve our understanding of typhoon-induced inland rainfall and highlight the need for enhanced track guidance in forecasting high-impact flood events.