Large-scale characteristics of landfalling tropical cyclones with abrupt intensity change

Abstract

Data from the China Meteorological Administration and ERA-Interim are used to examine the environmental characteristics of landfalling tropical cyclones (TCs) with abrupt intensity change. The results show that, of all 657 landfalling TCs during 1979–2017, 71%,70% and 65% of all landfalling TDs, TSs and TYs, respectively, intensify. Of all the 16595 samples, 4.0% and 0.2% of typhoons and tropical storms, respectively, experience over-water rapid intensification (RI) process during their life cycle. Meanwhile, 4.5% and 0.6% of typhoons and tropial storms, respectively, undergo overwater rapid decay (RD). These two kinds of cases, i.e., RI and RD, are used to analyze their associated large-scale conditions. Comparisons show that the RI cases are generally on the south side of the strong western Pacific subtropical high (WPSH); warm sea surface temperatures (SSTs) and sufficient water vapor fluxes existing in RI samples is a dominant feature that is conducive to the development of TCs. Also, the moderate low-level relative vorticity is favorable for TC intensification. On the contrary, the RD TCs are located on the west side of the WPSH; significant decreasing SSTs and low-level water vapor transport may synergistically contribute to RD. Simultaneously, low-level relative vorticity seems to be unfavorable for the development of TCs.