Core Viewpoint - The northern regions of China are experiencing increased rainfall and extreme weather events, raising concerns about climate change and its impact on regional weather patterns [1][3]. Group 1: Weather Patterns and Climate Change - The northern regions have seen multiple rounds of heavy rainfall since July, with 13 instances of heavy rain reported, which is 5 more than the average for the same period [1]. - The abnormal atmospheric circulation, particularly the western Pacific subtropical high, is a significant factor contributing to the increased rainfall in northern China [2]. - The onset of the rainy season in North China occurred on July 5, nearly two weeks earlier than the average date, marking the earliest start since 1961 [2]. Group 2: Implications of Extreme Weather - The increase in extreme weather events is linked to global warming, with the World Meteorological Organization reporting a fivefold increase in weather-related disasters over the past 50 years [3][4]. - Northern China is particularly vulnerable to extreme weather due to its ecological sensitivity, facing risks such as increased frequency and intensity of extreme events [4]. - The climate risk index for China in 2024 is projected to be the highest since 1961, with significant risks from flooding and high temperatures [3]. Group 3: Response and Adaptation Strategies - There is an urgent need for a comprehensive disaster risk reduction mechanism that includes government leadership, early warning systems, and community participation [4]. - The focus should be on risk assessment, dynamic monitoring, and public education to minimize exposure to extreme weather risks [4][5]. - The United Nations has initiated a global early warning initiative aimed at ensuring that everyone is protected by early warning systems by 2027 [5][6].

Group 1 - The article discusses the occurrence of "warm zone heavy rain" in northern China, particularly during a period of continuous heavy rainfall affecting regions like Beijing and Hebei [1][4] - "Warm zone heavy rain" is characterized by strong convective precipitation triggered by small to medium-scale weather systems in a high-temperature and high-humidity environment, without significant cold air involvement [4][6] - The phenomenon is typically localized, with hourly rainfall amounts reaching 50-100 millimeters, and the affected areas may only cover a few dozen square kilometers, making forecasting challenging [4][6] Group 2 - While traditionally associated with southern China, "warm zone heavy rain" can also occur in northern regions during critical periods, such as the transition from July to August [8] - The geological conditions and vegetation distribution in northern China are less capable of handling heavy rainfall, increasing the risk of geological disasters like flash floods and mudslides [8]

Group 1 - The article discusses the occurrence of "warm zone rainstorms" in northern China, particularly during a period of continuous heavy rainfall affecting regions like Beijing and Hebei [1][5] - "Warm zone rainstorms" are characterized by strong convective precipitation triggered by various weather systems in a high-temperature and high-humidity environment, without significant cold air involvement [1][3] - The phenomenon is localized, with intense rainfall rates of 50-100 millimeters per hour, and the affected areas can be as small as a few dozen square kilometers, making forecasting challenging [1][3] Group 2 - The formation mechanism of warm zone rainstorms is linked to the weak confrontation between cold and warm air, leading to the accumulation of moisture from the summer monsoon in northern regions [3] - Unlike traditional warm zone rainstorms in southern China, these rainstorms can also occur in northern regions during critical periods, such as "July to August" [5] - The geological conditions and vegetation distribution in northern China are less capable of handling strong rainfall, increasing the risk of geological disasters like flash floods and mudslides [5]

Group 1 - The current rainfall in multiple regions coincides with China's critical flood prevention period known as "July down, August up," which is characterized by complex and severe flood conditions each year [1] - The rainfall during this period mainly presents two forms: "frontal rainstorm" and "warm area convection" [3][5] - Frontal rainstorms occur when abundant moisture from the summer monsoon meets strong cold air, leading to intense and widespread rainfall [3] Group 2 - When the influence of cold air is weak or distant, the warm moist air accumulates in northern regions, creating a hot and humid environment, which can trigger small-scale strong convection [5] - The triggers for this convection include topographical uplift of warm moist air, sea-land breezes, and low-level jet streams, but this warm area convection typically does not result in regional heavy rainfall [5]

Group 1 - Beijing experienced heavy rainfall, with an average precipitation of 56.5 mm across the city from July 28, 20:00 to July 29, 07:00, and the maximum recorded at 184.2 mm in Fangshan Shilou [1] - Cumulative rainfall in Beijing from January 1 to July 29 reached 527.4 mm, which is 66.8% more than the average of 316.1 mm for the same period, and 68.4% more than last year's 313.2 mm [1] - Since the onset of the flood season on June 1, total rainfall has been 420.8 mm, exceeding the average of 240.7 mm by 74.8% and last year's 228.2 mm by 84.4% [1] Group 2 - The recent heavy rainfall in Beijing is attributed to an unusually northward and stable subtropical high-pressure system, which has led to frequent rain since July 24 [2] - A weather system known as the westerly trough influenced Beijing on the night of July 28, resulting in widespread rainfall across the city [2] Group 3 - Meteorological authorities have issued a yellow rainstorm warning, advising against driving through flooded areas and staying away from regions prone to geological disasters [3]

Core Viewpoint - The article discusses the impact of Typhoon "Zhu Jie Cao" on Beijing's rainfall, highlighting the indirect influence of the typhoon through moisture transport, leading to significant rainfall events in the region [2][3]. Group 1: Typhoon Influence - Typhoon "Zhu Jie Cao" has indirectly affected Beijing's rainfall by enhancing moisture conditions, although the primary influence comes from a high-altitude trough [2]. - The typhoon, which weakened on the 26th but regained strength, contributes to the moisture supply that enhances rainfall predictions for Beijing [2][3]. Group 2: Rainfall Predictions - Without the influence of the typhoon's moisture, the rainfall in Beijing would likely be less intense, but the current predictions indicate heavier rainfall due to the added moisture from the typhoon [3]. - Rainfall is expected to taper off after the daytime of the 29th, with a brief period of reduced precipitation before another significant rainfall event around August 3rd [4]. Group 3: Rainfall Characteristics - The rainfall distribution in Beijing is uneven, with some areas experiencing heavy rainfall while others remain dry, attributed to different weather systems affecting the region [4][6]. - The rainfall on the night of the 28th is characterized as a systematic and predictable weather event, although there are challenges in forecasting due to the influence of cold air and local topography [7].