Sideswiping Tropical Cyclones and Their Associated Precipitation over China

Tropical cyclone (TC) precipitation (TCP) has attracted considerable attention in recent decades because of its adverse socioeconomic impacts. In particular, considerable effort has been devoted to quantifying TCP and investigating the precipitation of TCs that make landfall. However, precipitation over land induced by TCs that do not make landfall (i.e., offshore), the so-called “sideswiping” TCs (STCs), is an important component of TCP but has attracted little attention from the research community to date. Here, best-track and daily precipitation data from the China Meteorological Administration during the 59 years of 1960−2018 are used to study STC precipitation (STP). Results show that: (i) the annual number of STCs fluctuates significantly from 3 to 17, with a mean frequency of 8.8 STCs per year; (ii) there are decreasing trends in STC frequency and STP amount over the past 59 years; (iii) both STC frequency and STP are high from July to October, with maxima in August; (iv) the distribution of STP, covering most of China’s coastal regions, is dominated by intense STCs, and the annual STP decreases from southeast coastal regions to northwest inland areas, with a maximum value over the islands of Taiwan and Hainan; and (v) extreme STP events could appear not only over the island and coastal areas, but also over inland areas such as Zhumadian of Henan Province due to the influences of local orography and favorable large-scale forcing.