今年华北雨季为何“超长待机”？专家解答↓

Group 1 - The core viewpoint of the articles highlights the unprecedented rainfall and extended rainy season in North China, marking it as the strongest since 1961 [2][6][13] - The North China rainy season began on July 5, 2023, which is 13 days earlier than the average, and lasted for 59 days, significantly longer than the typical 30 days [6][13] - The cumulative rainfall in North China has been exceptionally high, with some areas experiencing rainfall amounts 50% to 200% above the historical average [8][10] Group 2 - The rainfall has led to significant hydrological impacts, with 23 rivers exceeding warning levels, prompting a level IV flood defense response in Sichuan and Shaanxi provinces [1] - The rainfall has caused secondary disasters such as mountain floods and urban waterlogging, while also alleviating drought conditions in some regions [8][10] - The meteorological conditions contributing to this unusual weather pattern include abnormal sea surface temperatures in the equatorial Pacific and strong subtropical high pressure in the western Pacific [15]