Core Viewpoint - A significant rainfall event is expected to impact multiple provinces in southern China, with the potential for severe weather conditions and secondary disasters due to the heavy rainfall [1][3][7]. Summary by Relevant Sections Rainfall Impact Areas - The core impact areas for the upcoming rainfall include nine provinces: Sichuan, Chongqing, Hubei, Hunan, Henan, Jiangsu, Anhui, Guizhou, and Guangxi [3][4]. - Rainfall is expected to be concentrated in regions such as southern Shaanxi, eastern Sichuan, western Hubei, and southeastern Henan, with potential for heavy rain from June 19 to 21 [3][6]. Rainfall Intensity and Duration - The rainfall process is characterized by a long duration and significant cumulative rainfall, with some areas receiving over 100 millimeters, and localized regions potentially reaching 200 to 300 millimeters [3][6]. - Compared to historical averages, the intensity of this rainfall event is expected to be stronger due to the influence of a strong subtropical high and cold air masses [4][6]. Weather Patterns and Causes - The formation of this rainfall is attributed to the interaction of warm and cold air masses, leading to sustained heavy rainfall across the Yangtze River basin [4][6]. - The subtropical high is expected to shift northward, facilitating the movement of warm, moist air into the affected regions [4][6]. Secondary Disaster Risks - There is a heightened risk of secondary disasters such as flash floods and geological hazards in areas with significant rainfall accumulation, particularly in eastern Guangxi, northern Hubei, and southwestern Hunan [7][9]. - The rainfall is also expected to alleviate drought conditions in several regions, including the Sichuan basin and parts of Henan, while still posing risks of rapid transitions from drought to flooding [7][9].