Since the 19th, heavy rainfall has continuously affected the Jiangnan and South China regions, with cumulative precipitation in many areas breaking historical records in April. What is the reason for the recent heavy rainfall in the south? Will there be heavy rainfall and strong convection in the future? Monitoring shows that in recent days, the cumulative rainfall in many areas has reached 100 to 150 millimeters, with local areas in Guangdong such as Zhaoqing, Qingyuan, Shaoguan, Guangzhou, and Huizhou reaching 300 to 488 millimeters. As of Monday, 44 rivers in the the Pearl River basin had exceeded the warning flood. Why has there been so much rainfall in the south recently? The chief forecaster of the Central Weather Observatory, Ma Xueqian, introduced that since April, the subtropical high pressure has been stronger than the same period in previous years, which is conducive to the transport of water vapor from the South China Sea and the Bay of Bengal to the southern region. At the same time, the plateau trough and southern branch system are active, leading to frequent and prolonged heavy rainfall processes in the southern region. In addition, the temperature of the atmosphere in Jiangnan, South China, and other regions is significantly higher than the same period throughout the year. The atmosphere is rich in water content and has high unstable energy, leading to vigorous convective development and high rainfall intensity. The cumulative precipitation in many areas has broken historical records in April. According to the forecast, the range of heavy rainfall in Jiangnan and South China will shrink from the 22nd, but the precipitation will not completely stop. It is expected that in the next three days, there will still be rain in the eastern part of Jiangnan and the central and eastern parts of South China, among which there will also be heavy to rainstorm and local heavy rainstorm in central and southern Guangdong and southeast Fujian, accompanied by severe convection weather. How will the southern precipitation develop in late April? The mid-term weather forecast released by the Central Meteorological Administration shows that in late April, there will be significantly more rainfall in Jiangnan and South China, with frequent occurrence of severe convective weather. The cumulative precipitation in Jiangnan, South China, southern Sichuan Basin, and northern Guizhou is 50 to 120 millimeters, with some areas exceeding 400 millimeters; The precipitation in most of the above-mentioned areas is 50% to 80% higher than the same period in the year, and in some areas it is more than twice as much. Recently, Guangxi, Guangdong, Hunan, Jiangxi and other regions have experienced strong rainfall with highly overlapping areas, resulting in soil moisture saturation. Meteorological experts remind the public to be vigilant against potential disasters such as flash floods, mudslides, and landslides that may occur after heavy or sustained rainfall, to avoid going to mountainous and geological hazard prone areas, and to pay attention to preventing the adverse effects of strong convective weather. In addition, spring and summer are periods of high incidence of severe convective weather, with thunderstorms, hail, and other frequent occurrences that catch people off guard. Experts suggest that when paying attention to severe convective weather, corresponding preparations can be made for three different levels. During the possibility forecast stage issued by the meteorological department, the public can increase their attention and frequency to weather forecasts; After issuing a warning, consideration should be given to canceling travel plans, reducing outings, and strengthening infrastructure; When severe convective weather has arrived, move to a safe area as soon as possible and hide in sturdy buildings. (Lai Xin She)