Comparative analyses of the heavy rainfall associated with landfalling tropical cyclones SOULIK (1307) and MARIA (1808) with similar routes

Different rainfall evolutions associated with landfalling tropical cyclones (TCs) SOULIK (1307) and MARIA (1808) are analyzed before and after they made landfalls in Fujian province based on reanalysis data of the ERA5 and CMORPH data. The two TCs shared similar tracks, motion speed as well as landing points, but showed different asymmetric features of rainfall intensities and locations relative to routes. The results primarily exhibited the discrepancy of the inland rainfall distributions between the two TCs and the related influence factors. The constant torrential rain over land with the maximum on the left of the storm track associated with SOULIK was attributed to favorable dynamical conditions. The northeasterly outflow of SOULIK was reinforced by the easterly wave in upper-level, which induced strong divergence along with the distinct ascending motions by suction effect. The strong ambient VWS broke the warm core structure of SOULIK, which pointed to southsouthwest direction relevant to the strong northeasterly wind at 200 hPa, and further caused a more asymmetric rainfall pattern on the left of TC track. Besides, a cold intrusion was observed south of SOULIK in mid levels, enhancing convective instability coincident with the alternating circumstance of cold and warm advections from the lower layer to the upper layer over south of SOULIK, which further intensify the precipitation on the left of TC track. Simultaneously, the meridional moisture convergence owing to the enhanced southerly wind at lower level played a key role in the maintenance of severe rainfall south of SOULIK. Comparatively, the 48-h accumulated rainfall over land associated with MARIA was much weaker than that associated with SOULIK, and the maximum is on the northern side. The strong convergence in the lower level induced by the predominant easterly winds interacting with coastal terrains, as well as the distinct divergence coincident with the upper level jet in the southern part of the South Asia High (SAH), provide favorable dynamical conditions for the maximum rainfall north of MARIA. Simultaneously, the strong westerlies over the South China Sea, together with the eastern cyclonic system over the Northwest Pacific, create favorable moisture conditions for the rainfall on the northern side of MARIA. Results presented in this study provides an improved predictive understanding of physical mechanism dictating storm rainfall evolution from landfalling TCs, especially those with similar tracks