Chinanews client, Beijing, July 13th (Reporter Zhang Ni) In the past few days, North China and Huanghuai regions have ushered in the process of the strongest rainfall during the flood season. In this round of rainfall, the average rainfall in Beijing exceeded 100 mm.
According to the forecast of the Meteorological Department, this round of precipitation is the beginning of the rainy season in North China this year, and the rain will be frequented during the "seven lower and eight upper" periods.
People pass the intersection near Tuanjiehu in Chaoyang District, Beijing on July 12.
Photo by China News Agency reporter Jia Tianyong
Rainfall in many places breaks through historical extremes
In the past few days, the Beijing-Tianjin-Hebei region has experienced heavy rainfall, and the rainfall in some places has even exceeded the historical extreme.
Data from the Central Meteorological Observatory on the 12th showed that from an extreme point of view, local rainfall in Handan, Hebei, Jincheng and Changzhi in Shanxi, Jiyuan, Anyang and Hebi in Henan reached 220-342 mm (the maximum hourly rainfall was 102-125 mm).
In addition, the daily rainfall of 7 national stations in central and southern Hebei and northern Henan exceeded the extreme value in July. Among them, Jize (206.4 mm) in Hebei and Huaxian (211.7 mm) in Henan exceeded the historical extreme since meteorological records.
According to the precipitation (mm) from 18:00 on the 11th to 19:00 on the 12th released by the Beijing Meteorological Observatory: the city's average is 100.4, the urban average is 113.2, the southwest is 107.1, the northeast is 102.7, the northwest is 97.4, and the southeast is 75.8.
The city’s largest Chaoyang Sunhe Station is 164.1, and the city’s largest Yanqing Haizikou is 197.2.
Meteorologically, precipitation with a 24-hour precipitation greater than 25 mm is called heavy rain; 24-hour precipitation with a precipitation greater than or equal to 50 mm is called heavy rain.
This time, the average precipitation in Beijing has reached the torrential rain level, which also led to a significant reduction of flights at the two major airports in Beijing on the 12th, and the suspension of many bus lines at the same time.
The Beijing Municipal Commission of Transportation has launched an emergency plan for traffic flood prevention earlier.
In order to deal with emergencies such as water accumulation, landslides, and collapses on the road that may be caused by heavy rainfall, the transportation department has arranged more than 2,500 emergency flood control personnel, and more than 700 flood control vehicles and mechanical equipment.
Beijing ushered in heavy rainfall, and two cars parked on the side of the road were held down by tree branches.
Photo by Li Peiyun, China News Network reporter
Why is this rain so violent?
Why is the rainfall in the Beijing-Tianjin-Hebei region so rapid?
Regarding this issue, Zhang Fanghua, chief forecaster of the Central Meteorological Observatory, said to the media that this round of heavy rainfall has the characteristics of wide impact, high rainfall intensity, long duration, large accumulated rainfall, accompanied by strong convection and windy weather, and high disaster risk.
From the point of view of causes, this heavy rainfall process was affected by a deep low vortex system. The east side of the low vortex is accompanied by a strong low-level jet, which brings abundant water vapor and unstable energy, which is very conducive to the production of heavy precipitation.
The low vortex system moves slowly and the precipitation time is longer, which is conducive to the increase of accumulated precipitation.
In addition, the low-level jet stream converges and rises on the windward slope of Taihang Mountain, which is also conducive to local production of stronger precipitation.
In addition, corresponding to the low vortex, there is a cyclone system on the ground, with a large pressure gradient on the east side, which is conducive to generating strong ground winds.
At the same time, this process was accompanied by convective thunderstorms.
The two reasons are superimposed, and the windy weather in this process is also very obvious.
Image source: official website of the Central Meteorological Observatory
Don't charge rain gear! It's still raining in these places recently
According to the official WeChat account of the Beijing Meteorological Bureau, there were light to moderate rains in Beijing from the evening to the night of the 12th, and the rain gradually weakened in the second half of the night.
However, from the perspective of the whole country, the rainfall has not stopped.
The Central Meteorological Observatory issued a blue rainstorm warning at 18:00 on the 12th. It is expected that from 20:00 on the 12th to 20:00 on the 13th, some areas in northeastern Hebei, eastern Inner Mongolia, western and southern Liaoning, southern Shandong Peninsula, northern Jiangsu and other places are expected to be large. Heavy rains, including heavy rains (100-150 mm) in some areas of northeastern Hebei, southeastern Inner Mongolia and other places.
In addition, some of the above-mentioned areas are accompanied by lightning, short-term heavy precipitation and strong winds. The maximum hourly rainfall is 20-50 mm, the local area can exceed 60 mm, and the gusts are around 8.
The Meteorological Department predicts that from the 14th to the 20th, there will be more rainfall in North China, Huanghuai and other places, with strong rainfall around the 18th; in addition, there will be heavy rainfall in the Sichuan Basin from the 14th to the 16th.
In the coming week, the main precipitation belt will be concentrated in the east of Southwest China to North China, Huanghuai, and Northeast China, with a southwest-northeast trend.
The weather in the southern region, especially the Jianghuai, Jiangnan, and South China areas will be dominated by high temperature and little rain.
Meteorological experts reminded that immediately entering the "seven lower and eight upper" stage, the precipitation weather in North China and Northeast China is showing an increasing trend. The public should pay attention to the upcoming weather forecast, and should minimize unnecessary trips and do not go to mountainous areas, rivers, and areas with hidden geological hazards.
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