On the afternoon of July 2, as the high-altitude low-pressure trough gradually pressed southward, a large amount of monsoon water vapor was sucked into the North China Plain area. Groups of vigorously developed convective clouds quickly emerged in northern Henan and southern Hebei like boiling water bubbling. , and gradually moves east and north. Among them, a huge thunderstorm cloud group entered Shijiazhuang at about 6 o'clock in the evening, and continued to strengthen and move northward, sweeping the entire Shijiazhuang area.
The radar echo monitoring map of North China on the afternoon of July 2nd
From the radar echo, it can be seen that the intensity of the convective cloud group entering the Shijiazhuang area is very high, and it has shown an obvious deep red color on the radar, indicating that the intensity inside the cloud group is Convection activities are very intense, and violent weather processes such as thunderstorms, strong winds, hail, and short-term heavy precipitation are likely to occur on the ground. This is indeed the case from ground monitoring data. From 18:00 to 20:00 on the evening of the 2nd, Shijiazhuang experienced short-term heavy rainfall with hourly rain intensity exceeding 40mm from south to north, accompanied by thunderstorm winds of magnitude 8-10, and local short-term gusts as high as magnitude 11!
Under the influence of such violent wind and rain, on July 2, some netizens posted a video saying that in Taitou Village, Shangzhuang Town, Luquan District, Shijiazhuang, the top of the archway at the entrance of the village fell due to the extreme weather, causing many people taking shelter to be hit. It is suspected that eight people died. Then on the night of July 3, Shijiazhuang Luquan City issued an official announcement confirming the tragedy.
As a meteorological enthusiast, we don’t care whether the quality of the archway at the entrance of the village is acceptable or whether it was a tragedy caused by a shoddy project. Let’s talk about the possibility of this accident from the perspective of the power of extreme weather. nature, and some precautions against extreme weather.
Video screenshots taken by netizens
In recent years, with global climate warming, the word extreme weather has appeared more and more frequently. The definition of extreme weather is actually very simple. It is a very rare and influential weather phenomenon that occurs in a certain area, such as extreme high temperature, extreme low temperature, extreme heavy rain, etc., all belong to extreme weather. The most common and widely distributed in daily life are violent weather processes such as heavy rain, strong winds, thunder and lightning caused by strong convective weather .
Baidu entry definition
my country is the world's largest monsoon climate region. The summer monsoon breaks out, and a large amount of hot and humid vapor pours into the land, which can easily trigger large-scale strong convective weather. In strong convective weather, the impact of heavy rain often has a certain lag, and the penetration rate of lightning rods and in our country's buildings is now close to 100%. Therefore, the possibility of being attacked by lightning in daily life is also very small. The biggest impact is thunderstorms. The windy weather brought about it.
Strong winds in thunderstorm clouds are mainly caused by strong convective activities within the clouds. In the hot summer, strong updrafts on the surface promote the continuous development of clouds. Some clouds with intense convection will form a strong downdraft at the edge, which is called downburst in meteorology. Downdrafts like will quickly spread around after reaching the ground, setting off linear strong winds on the ground, with the maximum gust reaching level 15!
We know that the central wind force of a super typhoon is only level 16, so the wind force of level 15 is already comparable to the central wind force of a strong typhoon. Generally, strong winds of around level 10 are capable of blowing down trees and flying off roof tiles. An adult weighing about 120 pounds cannot walk against the wind. The thunderstorms and windy weather we usually talk about in weather forecasts are mainly caused by downbursts. Short-term winds can often reach level 8-10, causing huge damage to cities.
Strong winds knocked down street trees in Nantong on April 30 last year
In our country, due to the high incidence of strong convective weather, thunderstorms and strong winds occur very frequently, not only causing huge property losses, but sometimes even causing certain casualties.For example, a strong convection event occurred in Nantong, Jiangsu Province in the evening on April 30 last year. The windy weather blew down trees and billboards, causing a total of 11 deaths! On the afternoon of May 10 last year, Wuhan was hit by a severe thunderstorm. The glass windows of some buildings were blown out, and a large number of trees fell down along both sides of the river.
The scene after the strong convection disaster in Wuhan on May 10 last year
The downbursts in thunderstorms alone are already so powerful, not to mention the rarer tornadoes! Even the weakest EF0 level tornado has a maximum wind force of 15-16 levels, which can completely destroy everything, knock off roofs, and blow trucks into the air several meters high! For example, last year's tornado in Shengze, Jiangsu Province reduced all buildings within several kilometers to rubble, causing hundreds of casualties!
Pictures after the tornado in Shengze, Jiangsu
Therefore, the tragedy of eight people being killed when the archway fell in Shijiazhuang was most likely caused by a downburst attack caused by thunderstorm clouds. This kind of strong wind cannot be predicted based on the current level of science and technology. Even after the thunderstorm clouds are formed, it is impossible to determine where the strong wind will occur. Therefore, when encountering a thunderstorm, you must return to a nearby building as soon as possible and stay as far away from a stationary building as possible. Unstable objects, with the blessing of strong wind, even a piece of paper can have considerable power! The following are some precautions when encountering thunderstorms:
1. Do not stay on high-rise building platforms during thunderstorms. It is not advisable to enter isolated sheds, guard booths, etc. in open areas outdoors.
2. Stay away from exposed water pipes, gas pipes and other metal objects and electrical equipment in buildings.
3. It is not advisable to avoid thunderstorms under big trees. If you have to, you must keep a distance of 3 meters from the trunk of the tree, squat down and keep your legs close together.
4. If there is a feeling of ants crawling around your head, neck and hands during thunder and lightning, and your hair stands on end, it means that a lightning strike will occur. You should lie down on the ground quickly, which can reduce the risk of being struck by lightning, and wear it on your body. Metal jewelry and hairpins, necklaces, etc.
5. If you encounter a thunderstorm outdoors and you have no time to leave the tall object, you should immediately find some dry insulation and put it on the ground, and close your feet on it. Do not put your feet on the ground other than the insulation, because water can Conduct electricity.
6. When avoiding thunderstorms outdoors, you should be careful not to support the ground with your hands. At the same time, hold your knees with your hands, keep your chest close to your knees, and lower your head as much as possible, because the head is most vulnerable to lightning strikes than other parts of the body.
7. When you see lightning and hear thunder within a few seconds outdoors, it means you are in a dangerous environment near a thunderstorm. At this time, you should stop walking, put your feet together and squat down immediately. Do not pull together with others. It is best to use Plastic rain gear, raincoat, etc.
8. During thunderstorms, it is not suitable to hold an umbrella in the wilderness, or to hold high a badminton racket, golf stick, hoe, etc.; it is not suitable to play outdoor ball sports. It is very dangerous to play golf, football and other sports in thunderstorm weather; it is not suitable to Stay on and near the water; it is not suitable to wash clothes, fish, swim, or play by the river.
9. In thunderstorm weather, it is not advisable to drive a motorcycle quickly, ride a bicycle quickly, or run wildly in the rain, because the greater the stride of the body, the greater the voltage, and the easier it is to injure someone.
10. If you see a high-voltage line broken by lightning while outdoors, you should be more vigilant because there is a step voltage near the breakpoint of the high-voltage line. People nearby must not run at this time, but should put their feet together and jump away from the scene. .
Please pay attention to the latest weather changes in time, and don’t take chances! Always keep safety first!
