What are the characteristics of this fierce rainstorm in Henan?

According to the forecast of the Central Meteorological Observatory, since July 17, there has been continuous heavy precipitation in Henan, with heavy rain to heavy rain in many places and heavy rain in some areas.

Zhengzhou Flood Control and Drought Relief Headquarters issued an urgent notice on the 20th to upgrade the emergency response of flood control to Grade I. ..

The Zhengzhou Municipal Government urgently reminded the public that the situation in Zhengzhou was grim because of the heavy precipitation that had not happened for many years. Please stay at home or in a safe place as much as possible, pay attention to the surrounding environment, and improve the ability of waterproof, electricity prevention, disaster prevention, risk avoidance and self-help.

Source: Zhengzhou released

Why is the intensity of this precipitation process so great, why is it so long, and what is the future trend?

How heavy is the rain?

"This kind of precipitation is extreme. Five stations, such as Songshan, Yanshi, Xinmi, Yichuan and Dengfeng, have broken through the historical extreme value of daily precipitation since the station was established. Five stations, including Songshan, Gongyi, Xinmi, Yanshi and Dengfeng, broke through the historical extreme value of accumulated precipitation for three days since the establishment of the station. " Zhang Ning, chief forecaster of Henan Meteorological Observatory, said.

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Zhang Ning introduced that this precipitation has the following characteristics:

First, it lasts a long time. On July 17, there was a large-scale heavy precipitation in Henan Province, the western and central and western regions of Henan Province for four consecutive days, and the heavy precipitation will continue;

Second, the accumulated rainfall is large. The average rainfall in the whole province is 1 13.5 mm, and the average rainfall in Zhengzhou, Jiaozuo and Xinxiang is 357 mm, 2 10.6 mm and 194.5 mm respectively. The maximum precipitation occurred in Huancuiyu, Xingyang City, which was 728.0mm..

The third is large-scale heavy precipitation. There are 4,098 rainfall stations with rainfall exceeding 50 mm, 100 mm, 1.923 and 606 with rainfall exceeding 250 mm;

The period of heavy precipitation mainly starts from the night of 18, with heavy rain, heavy rain and local heavy rain in the northern, central and western regions.

Why is this rainstorm so strong?

What caused this heavy precipitation weather process? Zhang Ning introduced that the subtropical high in the western Pacific and the continental high were stably maintained in the Sea of Japan and the northwest of China respectively, which blocked the movement of the upstream system and led to the long-term maintenance of the low-value system in the westerlies in North China and Huanghuai.

"Affected by the deep easterly jet and the stable vortex shear, combined with the strong convergence and uplift of the easterly airflow caused by the special topography of Taihang Mountain and Funiu Mountain in Henan Province, the strong precipitation centers are mainly distributed in the western and northwestern mountainous areas of Henan Province, which are stable and less moving, resulting in the time precipitation of the governor of Henan Province." Zhang Ning stressed.

A picture tells you how big the rainstorm is in Henan! Image source: @ China Meteorological Observatory

Due to the long duration of precipitation and the concentration of heavy precipitation, the risk of geological disasters caused by mountain torrents in the western and northwestern regions has increased significantly, and the water levels of small and medium-sized rivers and reservoirs in the Yellow River Basin and Haihe River Basin have risen rapidly, which has also caused large-scale urban waterlogging and farmland waterlogging.

When will this heavy rain end?

"It is predicted that the heavy precipitation will continue until tomorrow night, and the concentrated areas of heavy precipitation are still in the northwest and central parts of Henan Province, and the precipitation can reach 100 to 250 mm, and the local area is 300 to 400 mm." Zhang Ning said that there was no obvious large-scale heavy precipitation weather and scattered thunderstorm weather in Henan Province from the 22nd to the 26th.

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In response to the precipitation process, Henan Meteorological Bureau strengthened accurate monitoring, meteorological satellites and a new generation of Doppler weather radar continuously observed for 24 hours, and encrypted ground and sounding monitoring time; At the same time, strengthen departmental linkage, roll out important meteorological information, meteorological information express and other decision-making service materials, conduct joint consultations for 8 times, and jointly issue meteorological risk early warning and forecast of mountain torrents geological disasters with water conservancy departments and natural resources departments; The whole network issued early warning information, and more than 1 100 were issued through SMS, WeChat, Weibo, website and other channels to remind the responsible person of more than 45 million times; Various new media in the meteorological department released more than 300 pieces of information such as forecast and early warning, rain conditions and popular science knowledge, covering more than 100 million people.