Structural characteristics of typhoons Jebi (2018), Faxai (2019), and Hagibis (2019)

Abstract

In recent years, Japan has experienced substantial damage from three intense typhoons: Jebi (2018), Faxai (2019), and Hagibis (2019). In this study, we provide a detailed description of the structure and synoptic environments of these typhoons, with particular focus on their frontal nature, temporal evolutions of the phase-space parameters, and the synoptic environments during their lifecycles. All three typhoons underwent phase changes at some point during their lifecycle before transitioning into extratropical cyclones. We found that their maximum intensities, as indicated by their maximum wind speed and minimum central pressure, occurred shortly after they transitioned from a cold-core to a warm-core structure. These typhoons displayed strong low-level convergence and upper-level divergence, along with favorable environmental conditions for strong convection before transitioning to extratropical cyclones. Our analysis suggests that the strong Typhoons Jebi and Hagibis had asymmetric structures with either deep warm or deep cold cores, whereas the relatively weak Typhoon Faxai had a symmetric deep warm core structure. Overall, our study provides valuable insights into the characteristics of intense typhoons and their transition to extratropical cyclones.