Climatology of Tropical Cyclone Extreme Rainfall over China from 1960 to 2019

Tropical cyclone extreme rainfall (TCER) causes devastating floods and severe damage in China and it is therefore important to determine its long-term climatological distribution for both disaster prevention and operational forecasting. Based on the tropical cyclone (TC) best-track dataset and TC precipitation data from 1960 to 2019, the spatiotemporal distribution of TCER affecting China is analyzed. Results showed that there were large regional differences in the threshold for TCER in China, which decreased from the southeastern coast to the northwest inland, with the maximum precipitation (578 mm) about 35 times higher than the minimum (16.1 mm). TCER occurred infrequently in northern China, but had a high intensity and was highly localized. TCER was characterized by group occurrence. The frequency and intensity of TCER showed slightly increasing trends over time and was most likely to occur in August (41.0%). Most of the TC precipitation processes with extreme rainfall lasted for four to six days, with TCER mainly occurring on the third to fourth days. TC with wide areas of extreme rainfall showed two types of prevailing landfalling tracks: a northwestward track and a westward track. On average, stronger (weaker) TC corresponded to more (less) extreme precipitation. However, there were exceptions and some weak TCs led to strong extreme rainfall. A total of 64.7% (35.3%) of the TCER samples occurred when the TC was centered over the land (sea). TCER≥250 mm was located within 3° of the center of the TC.