Core Viewpoint - The article discusses the characteristics and impacts of autumn typhoons in China, highlighting their increasing frequency and intensity compared to summer typhoons, as well as their potential for causing severe weather events and disasters [1][5]. Group 1: Typhoon Statistics - Over 40% of typhoons occur in autumn, with 859 autumn typhoons recorded from 1949 to 2024, closely following the 867 summer typhoons [1]. - Autumn typhoons exhibit greater peak intensity, with over 60% of typhoons in September and October reaching typhoon strength or above, peaking at 74% in October [1]. Group 2: Typhoon Path and Landfall - Autumn typhoons tend to make landfall further south compared to summer typhoons, primarily affecting Guangdong, Hainan, Taiwan, and Fujian, with Guangdong experiencing 72 landfalls [3][5]. - The shift in landfall locations is attributed to the movement of the subtropical high-pressure system, which influences the paths of typhoons [5]. Group 3: Historical Impact of Autumn Typhoons - Historically, nine autumn typhoons have made landfall in China as super typhoons from 1949 to 2024, with significant destructive potential [6]. - The strongest recorded autumn typhoon was "Marge" in 1973, causing over 900 deaths and extensive property damage in Hainan [6]. Group 4: Factors Contributing to Intensity - The combination of high sea temperatures and the presence of cold air masses in autumn increases the likelihood of stronger typhoons, as the temperature gradient enhances wind speeds [6]. - The interaction between autumn typhoons and cold air can lead to extreme rainfall and heightened disaster risks [6]. Group 5: Current and Future Impacts - The upcoming typhoon "Hua Jasha" is expected to impact southern China, potentially combining with cold air to produce extreme weather conditions [7].

Core Viewpoint - Typhoon "Jianyu" is currently a strong typhoon with maximum wind speeds of 38 m/s and is expected to continue moving northwest at a speed of approximately 20 km/h, with potential for further intensification [1][4]. Group 1: Typhoon Characteristics and Movement - Typhoon "Jianyu" is located about 150 kilometers southeast of Sanya, Hainan, and has maintained a fast-moving characteristic, averaging 24 km/h since entering the South China Sea [1]. - The typhoon's structure is tight and complete, indicating that its intensity is unlikely to weaken significantly, regardless of whether it makes landfall or passes near Hainan [4]. - The expected trajectory suggests that "Jianyu" will likely pass close to the southern coast of Hainan, with a possibility of landfall between Sanya and Ledong [4]. Group 2: Weather Impact and Precautions - The typhoon is expected to bring heavy rainfall to Hainan, with areas like Yongxing Island experiencing extreme rainfall of 503.1 mm [1]. - Coastal regions are advised to prepare for strong winds and heavy rain, particularly in southern Hainan and mountainous areas, where localized heavy rainfall and secondary disaster risks should be monitored [4]. - The outer spiral rainbands of "Jianyu" are anticipated to affect regions such as the western and northern Sichuan Basin, necessitating attention to hydrological and geological disaster risks [4]. Group 3: Seasonal Classification - Typhoon "Jianyu," generated at the transition between summer and autumn, exhibits characteristics more akin to summer typhoons, primarily influenced by the subtropical high pressure [5]. - Autumn typhoons typically have more complex paths due to the weakening of the subtropical high, which is not the case for "Jianyu" [5]. Group 4: International Cooperation - The China Meteorological Administration has enhanced communication with Vietnam's meteorological authorities to jointly monitor and prepare for the impacts of Typhoon "Jianyu" as it approaches Vietnam's central and northern coasts [6][7]. - The collaboration includes sharing critical forecast information regarding the typhoon's path and potential intensity upon landfall in Vietnam [7].