Group 1 - The article discusses the extreme convective weather that occurred in Beijing's Miyun, Huairou, and Yanqing districts due to the influence of warm and humid airflow from the edge of the subtropical high-pressure system [1] - Meteorological experts indicate that Beijing has entered the main flood season, with a significant increase in the probability of heavy rainfall events during this period [1] - The article emphasizes the need for public awareness and preparedness for potential geological disasters such as flash floods and landslides due to frequent rainfall in the coming days [1] Group 2 - The Beijing Center for Disease Control and Prevention advises the public to pay attention to drinking and food hygiene during the rainy season, recommending against using rainwater for washing fruits and utensils [2] - It is suggested that individuals should wash any skin areas that come into contact with rainwater promptly to prevent skin diseases [2]

Group 1 - The main flood season in China varies by region, with the Northeast and North China experiencing it from July to August, while the Yangtze River basin has its peak from June to August, and South China from April to October [1][3][5][7] - The critical flood prevention period in North China and Northeast is from July 16 to August 15, known as "July down, August up," during which urban flooding and river dam risks are prevalent [3][5] - The Yangtze River basin experiences a "plum rain" period from late June to early July, characterized by continuous rain and high humidity, often accompanied by thunderstorms [5] Group 2 - Flood warning levels are categorized into two: warning water level and guarantee water level, which indicate the state of flood defense readiness [10] - The warning water level signifies a state of alert for flood defenses, while the guarantee water level represents the maximum water level that can be safely managed by flood defenses [12] - Floods are classified and numbered when they exceed historical records or reach significant scales that threaten local flood safety, prompting public awareness [13][15]

Core Insights - The South China Sea summer monsoon has erupted this week, which is later than the usual onset time, indicating the beginning of the East Asian summer monsoon [1] - Following the eruption of the summer monsoon, the monsoon rain belt will gradually advance from South China northward, leading the country into the main flood season [1]

Core Insights - The China Meteorological Administration forecasts the strongest rainfall event of the year in southern China from today (27th) to the 29th, marking the onset of the main flood season [1] - The rainfall is characterized by significant cumulative amounts and intense short-duration precipitation [1] Summary by Region - The areas of focus for the heaviest rainfall include the central and southern parts of Hunan, central Fujian, northern Guangdong, and northern Guangxi, with cumulative rainfall expected to exceed 100 millimeters [1]