Since July this year, heavy rainfall has caused waterlogging and mountain torrents in many parts of southern China. After July 24, Jiangnan, Southern China, and Xinjiang have continued to be hot. Beijing and Tianjin have also joined the ranks of high temperatures, with the highest temperature exceeding 35℃; more abnormal Yes, typhoons that frequently landed in China in July have rarely been absent this year. What is the connection between the two? The reporter interviewed relevant experts from China Meteorological Administration.
The July torrential rain is temporarily ending, and many places in the south of the Yangtze River and southern China will usher in a high temperature of 40℃
Chen Tao, chief forecaster of the Central Meteorological Observatory, introduced that with the northward rise of the subtropical high, the rainfall in the middle and lower reaches of the Yangtze River tends to end on July 29, and the rain belt that has been entrenched in the Yangtze River for many days has begun to move north.
The heavy rainfall on July 27 was mainly concentrated in the middle and lower reaches of the Yangtze River, with strong rainfall in Hunan, Hubei, and Anhui.
By July 28, rainfall in the middle and lower reaches of the Yangtze River will be significantly weakened. At the same time, the weather situation in the north will also undergo a turning point. With the arrival of the main flood season, the rain will increase significantly. Light to moderate rain or thunderstorms prevailed in North China and Northeast China, while heavy rain or heavy rain occurred locally in central Hebei.
Chen Tao introduced that in Jiangnan and South China, where the “flammation value” remained high under the control of the subtropical high in the early stage, the high temperature will continue in the next few days, and the Sichuan Basin will also be high. In the next three days, there will be high temperatures above 35°C in southern China, southern Jiangnan, western Inner Mongolia, Sichuan Basin, southern Xinjiang and Turpan Basin, among which southern Hunan, southern Jiangxi, northern and southern Guangdong, and central Hainan Island. The highest temperature in the region is 37°C to 39°C, and it can reach 40°C locally.
This year will usher in the first July "empty station" since 1949
This year, heavy rains and high-temperature weather have continued. The strange thing is that July is almost over, so far no typhoon has landed in my country. Chen Tao said that the Central Meteorological Observatory predicts that tropical storms will not form in the Northwest Pacific until early August and may land on the coast of my country.
Where did the typhoon go? Jia Xiaolong, deputy director of the National Climate Center, said that in general years, 26 to 27 typhoons will be generated in the western Pacific region of the South China Sea, of which 6 to 7 will land in my country. Only two typhoons have been generated so far this year, and no typhoon has been generated in July. Since the beginning of summer this year, the subtropical high has continued to be strong and southerly, which has greatly suppressed convective activities in the tropical western Pacific, where the typhoon originated. It lacked the most critical environmental conditions and squeezed the typhoon’s living space.
Jia Xiaolong said that the long-term strong subtropical high this year has not only reduced the number of typhoons in its control center, but also caused the early arrival of the plum in Jiangnan and other places and continued heavy rains.
How did this abnormal climate form? Jia Xiaolong said that my country is in a sensitive area of climate change. Since 1961, the frequency of heavy rains has increased significantly, and the number of heavy rains has increased by 3.9% every ten years. A weak El Niño event began last autumn. At the same time, the North Indian Ocean sea temperature was unusually warm, and the subtropical high pressure was significantly stronger. The air currents continuously transported water vapor from the Indian Ocean and the Pacific to southern China. The strong cold air in the north was active and the cold air moved south. The cold and warm air meet in the middle and lower reaches of the Yangtze River, making the Meiyu front stronger and more rainfall. According to forecasts, in August, as the subtropical high rises to the north, my country's rain belts rise to the north, and most of the south may be controlled by the subtropical high, and a climate of continuous sunny, hot, high temperature and little rain will appear.
Pay attention to flood conditions in the north
Jia Xiaolong said that now is the main flood season. In the future, there may be serious floods in the Haihe River Basin, the upper and middle reaches of the Yellow River, the Songhua River Basin and the Liaohe River Basin in the north. In the later period, we must also pay attention to the impact of the northern flood on all aspects.
Zhu Dingzhen, chief expert of meteorological services at the Public Meteorological Service Center of the China Meteorological Administration, said that my country has a vast territory. With the northward movement of the rain belt, the southern region of the Yangtze River and the middle and lower reaches of the Yangtze River have "been blooming" and the rainy season in North China has begun. In Northeast China, the Huaihe River Basin and other northern regions, there are often insufficient preparations for flood prevention. Therefore, when extreme weather conditions occur, special attention should be paid to flood prevention preparations.
(Our reporter Yuan Yufei)