Important heavy rain events in China from April to October in 2017

Based on daily precipitation data at more than 2 400 national automatic weather stations and operational synoptic charts, we have conducted a statistical analysis of the important heavy rain events in China occurred between April and October in 2017 by comparing them to the 30-year mean precipitation during 1981-2010. A survey of the synoptic condition, rainfall duration, rainfall area and accumulative amount of precipitation for these events is then presented. Results indicate that there were 184 heavy rain days and 35 important heavy rain events in China during the study period, of which 20 events appeared in Southern China. The number of days and the frequency of heavy rain between April and October in 2017 were less than the same period in recent 10 years. Several persistent rainstorms, which caused several drainage and regional floods, occurred in the southern China. The accumulated precipitation at Lufeng station in Guangdong from June 14 to 17 in 2017 amounted to 586.4 mm, which was the maximum precipitation value at single station in this year. The autumn rain from West China to the Huaihe River basin was obviously higher than normal, resulting in serious floods and geological disasters. Extreme precipitation events occurred frequently. The annual precipitation of many stations such as Guangzhou, Guangdong, Yongji, Jilin and Yulin, Shanxi broke the corresponding period or historical records. In 2017, there were 8 typhoons landing in China, whose time and location of landing were relatively concentrated. Typhoon and rainstorms attacked Guangdong, Fujian and other places many times in this year.