Observational characteristics and causes of extreme heavy rainfall in typhoon Duksuri (2305)

Abstract

Super Typhoon Duksuri (2305), made landfall in Fujian Province, causing significant impacts from July 27th to July 31st. The typhoon resulted in heavy to torrential rainfall in multiple provinces, particularly in southern Taiwan, eastern Fujian, and the Beijing-Tianjin-Hebei region. Daily accumulated precipitation reached a maximum of 200 to 220 millimeters. Using ERA5 reanalysis data and NCEP Climate Forecast System Version 2 reanalysis data, this article conducted an observational analysis of Duksuri. The results indicate that the interaction between subtropical high-pressure systems, typhoons, and the strong southeast and east winds created favorable conditions for the prolonged duration of Duksuri and extreme precipitation. The extreme rainfall in southern Taiwan and eastern Fujian was primarily caused by the abundant moisture associated with the typhoon itself. In contrast, the extreme rainfall in the Beijing-Tianjin-Hebei region was primarily due to the northward movement of the remnants of the typhoon, hindered by the high-pressure systems, resulting in longer and concentrated precipitation. Additionally, both regions are located on the windward slopes of mountainous areas, which significantly enhance the rainfall due to orographic lifting.