An Overview of the 2021 Tropical Cyclone Features in the Western North Pacific Region

As extreme events are getting more frequent in a changing climate, attention has been paid to the anomalous tropical cyclone (TC) features within a single year. The 2021 TC features in the Western North Pacific (WNP) are analyzed in this study. The result shows that more than half of TCs in 2021 can only reach an intensity of the tropical storm category, and 2021 TCs preferred a northeastward drift direction. August 2021 is identified to be one of the major contributors to these scenarios. Influenced by the strong southwest monsoon in early August 2021, TCs Lupit, Mirinae and Nida kept drifting northeastward since their genesis. Although their tracks were nearly parallel, few interactions among them can be detected due to the instantaneous large mutual distance and low TC intensity. Regarding the relatively low TC intensity in August 2021, it is confirmed that the intensification of TCs Lupit and Mirinae was restrained by the terrain effects along the track, while with the insufficient moisture flux convergence perhaps caused by the adjacent subtropical high, TCs Nida and Omais lacked an environment favorable for the intensification. The present study provides an overview of the TC features in WNP with a special focus on the 2021 August scenario, which could enhance the academic community’s understanding of extreme climate events and provide potential assistance for future disaster prevention and mitigation efforts in coastal areas.