Core Viewpoint - The recent heavy rainfall in Guangdong is attributed to a combination of meteorological factors, including a low vortex system and the southwest monsoon, leading to significant flooding and related disasters in the region [1][4][5]. Group 1: Causes of Heavy Rainfall - The heavy rainfall is primarily caused by a low vortex system, which acts similarly to a typhoon but is generated over land, creating strong upward airflows that draw in moisture [4]. - The southwest monsoon is providing ample warm and moist air, which fuels the rainfall [4]. - The interaction between the low vortex and the southwest monsoon has been ongoing since early August, leading to continuous heavy rainfall in Guangdong [4]. Group 2: Impact and Consequences - The rainfall has resulted in urban flooding, fallen trees, and even landslides, with cities like Guangzhou, Zhaoqing, and Qingyuan being significantly affected [1][4]. - The phenomenon known as the "train effect" has caused successive thunderstorms to impact the same areas, exacerbating the rainfall intensity [4]. Group 3: Forecast and Future Conditions - Meteorological authorities predict that the heavy rainfall will cease by August 7, as the low vortex moves away from Guangdong [7]. - Following the rain, temperatures are expected to rise, with highs ranging from 34°C to 37°C, as the subtropical high-pressure system regains control [7].

Summary of Key Points Core Viewpoint - The recent continuous rainfall in Guangdong has raised questions among residents regarding its intensity, causes, and duration, with significant weather warnings issued across the region [2][3]. Group 1: Rainfall Intensity - Shenzhen issued a citywide red rainstorm warning for the first time since Typhoon "Mangkhut" in 2018, indicating severe weather conditions [3]. - Hong Kong recorded 355.7 millimeters of rain on August 5, breaking the record for the highest daily rainfall in August since 1884 [3]. - Over a 24-hour period, 28 towns in Guangdong experienced extreme rainfall, with the highest recorded at 470.6 millimeters in Huizhou [5]. Group 2: Causes of Rainfall - The rainfall is attributed to a combination of uplift mechanisms and abundant moisture, with a cold vortex acting similarly to a typhoon, creating strong upward motion and drawing in moisture [6][8]. - The southwest monsoon has been a significant contributor, bringing warm, moist air into Guangdong, which, combined with the cold vortex, has led to persistent heavy rainfall [8][10]. Group 3: Comparison with Northern Rainfall - The rainfall in Guangdong differs from that in northern regions, as the latter is influenced by cold air masses and warm moist air converging, while Guangdong's rain is more akin to typhoon rain mechanisms [10][11]. Group 4: Future Weather Outlook - The cold vortex is expected to move out of Guangdong, leading to a decrease in rainfall intensity as the subtropical high pressure pushes the system northward [14]. - After the rain subsides, temperatures in Guangdong are anticipated to rise, transitioning to a hot and humid weather pattern [15][17].

Core Insights - The strongest rainfall since the onset of the flood season has affected 14 provinces and regions in southern China from June 17 to 23, with many areas breaking historical daily rainfall records [1][2] - The cumulative rainfall in provinces such as Guangxi, Guizhou, Hunan, Hubei, and Anhui reached between 400 to 700 millimeters, with some localities exceeding 1,118 millimeters [2][3] - A new round of strong rainfall is expected to follow immediately, impacting areas including Sichuan and Chongqing, although the intensity and range will be less than the previous event [4][6] Rainfall Data - Specific extreme rainfall records include: - Hubei Hefeng: 328.4 mm on June 19 - Guizhou Zhijin: 279.7 mm on June 19 - Guangxi Tian'e: 208.7 mm on June 23 - Hunan Longshan: 205.8 mm on June 19 - Jiangsu Hongze: 191 mm on June 20 - Jiangsu Binhai: 189 mm on June 20 [3] Meteorological Analysis - The intensity of the rainfall is attributed to favorable conditions for moisture and energy, with the positioning of the subtropical high-pressure system causing persistent rainfall in the Yangtze River region [3] - The interaction of cold and warm air masses at the edge of the subtropical high-pressure system has led to prolonged heavy rainfall, with both cold vortices and subtropical high-pressure being stronger than usual [3] Upcoming Weather Forecast - From now until June 27, another round of strong rainfall is anticipated, particularly affecting the eastern part of the southwest region and areas like Jianghan and Huanghuai [4][6] - The core impact period for this new rainfall event is expected to be tomorrow and the day after, with significant rainfall predicted for regions from Guizhou to southern Henan [6] - Areas previously affected by heavy rainfall may experience cumulative rainfall exceeding 200 millimeters, raising concerns about potential secondary disasters such as landslides and mudslides due to saturated soil conditions [4][6]