ABSTRACT Based on the 6‐hourly tropical cyclone (TC) best track dataset and global reanalysis data, this study investigates the statistical characteristics and potential influencing factors of rapid weakening (RW) of TC in China's offshore area during 1980–2023. Statistical analyses indicate that TC RW in China's offshore area has experienced a statistically significant increase since 1980. The TC RW occurs more frequently in September and the RW rate peaks in December. Specifically, RW cases to the northeast of Taiwan occur predominantly during the TC active season (June–September), while RW cases to the southwest of Taiwan (in the South China Sea) are skewed toward early or late stages of the TC active season. Analysis of influencing factors on RW TCs reveals that the offshore RW of TCs has statistically significant correlations with sea surface temperature (SST), upper‐level divergence (DIV200), deep‐layer vertical wind shear (VWS), and TC fullness (TCF) with the statistical significance over the 99% confidence level. Compared to slow weakening (SW) cases, RW events usually occur when TCs with larger TCF cross regions exhibiting lower SST, stronger VWS and enhanced DIV200. Furthermore, the factors affecting RW in southern and northern China's coastal sea are analysed. RW in the northern offshore area is strongly influenced by SST gradient, particularly showing a significant positive correlation with the meridional SST gradient (SSTGMER). In contrast, RW in the southern offshore region is more affected by the zonal SST gradient (SSTGZON). This distinction is mainly attributable to differences in directions of TC movement between the two regions. DIV200, mid‐level relative humidity (RH500‐700) and TCF are also significantly correlated with RW in the southern offshore coast, whereas these factors have no significant relationships with northern RW TCs.
Xue et al. (2026) studied this question.