Review of Climatology and Favorable Environmental Conditions of Tornado in China

Although the occurrence probability of tornadoes in China is extremely low, several intense tornado events have received a great deal of attention in recent years. This paper summarizes the research progress on the climatological distribution characteristics, circulation backgrounds and environmental conditions of tornadoes in China, including the overall climatology and the climatology of tropical cyclone (TC) tornadoes, as well as the environmental conditions of tornadoes occurring inside the Meiyu systems, cold vortex and TC. In addition to the central plain areas in the eastern part and central part of China which frequently experience tornadoes, attention should also be paid to the northern Hebei and southeastern Inner Mongolia border areas with Liaoning. In addition, weak tornadoes also occur in the Qinghai Tibet Plateau. TC tornadoes occur about 5 times per year on average. The most intense tornadoes recorded in China reached EF4, with 7 tornadoes recorded from 1951 to 2020. The synoptic background for more tornadoes in China is Meiyu, cold vortex and TC. Strong tornadoes under the background of Meiyu usually have all the favorable conditions of mesocyclone tornadoes. The low-level humidity of tonado environment under the cold vortex is low, while the convective available potential energy of TC tornado is weaker (200-1000 J / kg). It is necessary to establish a reliable database of tornado cases in China, and the environmental conditions and mechanisms of mesocyclonic and nonmesocyclonic tornado still need to be further studied.