Henan suffered extremely heavy rainfall. Why was the rainfall so violent?

Zhang Juan, a meteorological analyst at China Weather Network, said that due to the influence of the low vortex system in this area of ​​​​Henan, and the continuous replenishment of low-altitude easterly water vapor, coupled with the uplift of the terrain in the Taihang Mountains, resulting in Such heavy rainfall.

The Henan Provincial Meteorological Observatory predicts that July 20 to July 21 will still be the main period of precipitation in Henan. From day to night on July 20, the province will be cloudy with light to moderate showers and thundershowers, among which There will be heavy to heavy rains, local heavy rains or extremely heavy rains accompanied by short-term heavy rainfall in the seven regions north of the Yellow River, Sanmenxia, ​​Luoyang, Pingdingshan, Xuchang, Shenhe, Zhengzhou, Kaifeng, the west of Shangqiu and Zhoukou, and the northern part of Nanyang. , short-term strong winds and other strong convective weather.

The characteristics of this precipitation process

First, it lasts for a long time. Beginning on July 17, Henan Province, western and central and western regions of Henan Province experienced widespread heavy rainfall for four consecutive days, and heavy rainfall will continue. ?

Second, the accumulated rainfall is large. The average rainfall in the province is 113.5 mm. The average rainfall in Zhengzhou, Jiaozuo and Xinxiang are: 357 mm, 210.6 mm and 194.5 mm respectively. The maximum precipitation occurred in Huancuiyu, Xingyang City, with 728.0 mm. ?

Third, heavy rainfall covers a wide range. There are 4,098 rainfall stations in the province with rainfall exceeding 50 mm, 1,923 with rainfall greater than 100 mm, and 606 with rainfall greater than 250 mm. ?

Fourth, periods of heavy rainfall are concentrated. The heavy rainfall period mainly started on the night of the 18th, with widespread heavy rains, heavy rains, and local heavy rains in the northern, central, and western regions. ?

Fifth, it is extreme. Five stations including Songshan, Yanshi, Xinmi, Yichuan and Dengfeng have exceeded the historical extreme value of daily precipitation since the station was established. Five stations including Songshan, Gongyi, Xinmi, Yanshi and Dengfeng exceeded the historical extreme value of cumulative precipitation in the three days since the station was established.