On the afternoon of October 3, with the appearance of a large-scale rain belt on the cloud map of the Fengyun-4 satellite in the eastern part of the northwest region of northern China to the northeast of North China, it was announced that another round of large-scale rain in northern China was starting, and the clouds in some areas were still very dense and expanded, indicating that the rainfall in some areas was still relatively intense.
For example, today, Liaoning has issued a hail red warning, a red warning for heavy rain, and a red warning for thunderstorms and strong winds, and in the forecast, it is proposed that there are 13 winds in local areas, which is not only unprecedented before October, but also rare in the middle of summer. This is related to the large-scale hot weather in the south and even local high temperatures to break records, because the south is controlled by the unusually strong western Pacific subtropical high pressure, the weather is particularly hot, and the subtropical high pressure also pulls the unusually strong warm and humid water vapor to the north, bringing extra ample atmospheric energy, so today's rain in the north today is not like the autumn rain, more like the intensity of summer. In addition to Liaoning, thunderstorms in Henan, Shandong, Hebei and other places are also quite irritable, and in many places, thunderstorms, winds, hail and other fierce weather have appeared
The forecast of the Central Meteorological Observatory has pointed out that it is expected that from October 3 to 5, there will be a continuous and heavy rainfall process in parts of northern China. There is moderate to heavy rain in the Sichuan Basin, the eastern part of the Northwest Region, the north china, the northern part of Huanghuai, the southern part of the Northeast region, and some areas have heavy rainfall, and the northern part of the Sichuan Basin and other local areas have heavy rainfall, and the cumulative rainfall in some areas can reach more than 200 mm.
In the past September, many places in the north have seriously too much rain, soil moisture is close to saturation, many rivers rarely ushered in the autumn flood, in the next rainy situation, October rainy, too wet soil, high river water level will continue - recently, the Yellow River has formed the No. 1 and No. 2 flood peaks of this year because of the rain, and on October 2, the peak of the flood reached the Xiaolangdi Reservoir, which is very rare in the history of October. From the existing observation data, the flow of the main stream of the Yellow River is still not small, the flow of the Huayuankou Station in the southern section of the Yellow River reaches 4850 cubic meters per second, and the flow rate of Aishan Station in Liaocheng, Shandong Province reaches 5260 cubic meters per second, which is quite a rare level in October.
But in contrast, the annual flow of the Pearl River is the second in the country, the recent water level is unusually low, the main stream of the Pearl River (Xijiang) Guangxi Wuzhou Station flow is only 2100 cubic meters / second, less than one-half of the Yellow River, the largest flow in Guangdong Zhaoqing Gaoyao Station, the flow of 3470 cubic meters / s, but also less than the Yellow River, then some netizens have to ask: This is the southern climate is desertification? Are you really going to start the North-South Water Diversion Project?
The main reason for this change is the weather pattern of continuous "north rain and south heat" in China in recent times, and there is less rain in many places in the south. In the short term, this may be related to this year's La Niña phenomenon. La Niña has a very important influence on the global weather and climate. One of the influences on China is to interfere with the rainfall in the autumn and winter seasons in the south of China, so that the precipitation in Jiangnan, South China and other places is less than the same period of the year, so the lack of rain in many places in the south in recent times may be related to La Niña. As for whether the long-term climate is desertified, it still needs to be continuously observed.