China News Service, Beijing, July 20 (Reporter Liu Liang) Henan has experienced continuous heavy rainfall. Since July 17, there have been heavy rains and heavy rains in many places, and extremely heavy rains have occurred in some areas.
Why is the intensity of this precipitation process so large, why is it lasting so long, and what is the impact?
On July 20, Henan experienced continuous heavy rainfall, with heavy rains and heavy rains in many places, and extremely heavy rains in some areas.
Zhengzhou City has upgraded its flood control emergency response to level I, and continuous heavy rainfall has caused serious water accumulation in some streets.
Photo by China News Agency reporter Kan Li
Analysis by the Henan Meteorological Department pointed out that the heavy rainfall in Henan was mainly concentrated in the western, northern and central regions, and extremely heavy rains occurred in Zhengzhou, Jiaozuo, Xinxiang, Luoyang, Nanyang, Pingdingshan, Jiyuan, Anyang, Hebi, and Xuchang.
The precipitation process has the characteristics of long duration, large accumulated rainfall, wide range of heavy rainfall, concentrated periods of heavy rainfall, and extremes.
According to analysis, the cause of the heavy precipitation weather process is that the western Pacific subtropical high and the continental high remained stable in the Sea of Japan and Northwest China, respectively, blocking the movement of the upstream system, causing the low-value system of the westerly zone to grow in the North China and Huanghuai regions. Time is maintained.
Affected by the deep easterly jet and stable low vortex shear, combined with the strong convergence and uplifting effect of the special topography of the Taihang Mountain and Funiu Mountain in Henan Province on the easterly airflow, the heavy precipitation centers are mainly distributed in the western and northwestern parts of Henan Province. The area is stable and less moving, causing long-term precipitation in Henan.
Due to the relatively long duration of precipitation and the concentrated areas where heavy precipitation occurs, the risk of mountain torrents and geological disasters in the western and northwestern mountainous areas has increased significantly. The water levels of small and medium rivers and reservoirs in the Yellow River Basin and Haihe River Basin have risen rapidly, and large-scale cities have also been caused. Waterlogging and waterlogging of farmland.
How long will the heavy rain weather last?
On the evening of the 20th, the Henan Meteorological Department predicted that the heavy precipitation will last until the night of the 21st. The heavy precipitation area is still in the northwest and central Henan, and the precipitation can reach 100 to 250 millimeters, and locally 300 to 400 millimeters.
From the 22nd to the 26th, there was no obvious large-scale heavy precipitation in Henan, and there were polydispersive thunderstorms in the province.
(Finish)