Statistics of warm-season hourly extreme precipitation in the Sichuan Basin, China during 2002–2021.

This study examines hourly precipitation data from 128 national meteorological observation stations within the Sichuan Basin (SB) spanning 2002 to 2021, focusing on warm-season (May to September) hourly extreme precipitation (HEP) and its events (HEPEs). Significant spatial variability is observed across the SB regarding thresholds, amount, intensity, and frequency of warm-season HEP. HEP predominantly occurs from mid-July to early August, with a higher probability of peak events in the afternoon during these months. HEPEs starting from midnight to early morning tend to have prolonged durations, whereas, in the afternoon, prompt-duration HEPEs lasting within 3 h are more prevalent. Around the basin, the northwest and northeast regions experience HEPEs with higher precipitation amounts but fewer occurrences. The northwestern region encounters shorter-duration HEPEs with greater rainfall intensity, while the northeastern region records a higher frequency of moderate or weak HEPEs lasting ≥ 13 h. Comparatively, the southwestern basin exhibits a higher frequency of nocturnal HEP events characterized by relatively lower rainfall intensity. The eastern Sichuan parallel ridge-valley area in the southeastern basin demonstrates more frequent HEP occurrences with lower rainfall intensities. Additionally, mountainous regions of the southeastern SB and the southern branch of the eastern Sichuan parallel ridge-valley exhibit lower HEPE amounts but greater numbers of events, primarily characterized by prompt-duration events in the afternoon. These findings unveil the diverse spatiotemporal patterns of warm-season HEP and HEPEs within the SB, highlighting the regional variability across different geographical zones. This study provides insights for managing vital resources and timely natural disaster evacuation. [ABSTRACT FROM AUTHOR]