Recently, the South China is in a long rainy season. Yesterday, the news of the heavy rain in Beijing also became a hot topic. It became a subject of widespread concern. So what is the difference in this rainfall and can cause such great concern? According to meteorological experts, this heavy rainfall process is a so-called vortex torrential rain. Then, what is a vortex torrential rain? What are the characteristics of cold vortex rainstorm? How should we defend it?

Do you really understand "storm"?

Heavy rain is the rainfall with high rainfall intensity (the amount of rainfall per unit of time is called rainfall intensity). The Chinese Meteorological Administration stipulates that rainstorms with 24 hours of rainfall greater than or equal to 50 millimeters , heavy rainstorms with greater than or equal to 100 millimeters , and greater than or equal to 200 Millimeters are particularly heavy rain.

Why isn't this rainfall a "special storm"?

The heavy rainfall process is mainly affected by the slow vortex moving eastward. Under the influence of the low eddy weather system, the water vapor convergence is obvious and the upward movement is strong. In addition, the low vortex movement is slow and the precipitation duration is long, and it is easy to form heavy rain weather.

According to the current forecasting results, the accumulated rainfall during the rainfall in most parts of Beijing can reach torrential rainfall ( 60 to 100 mm), and rainfall in front of the western piedmont and northeastern areas can reach heavy rains ( 120 to 180 mm). ) The maximum hourly rainfall was 40 to 60 mm, which did not reach the extreme storm level.

What is a vortex storm?

The so-called cold vortex is a cold vortex system that rotates at a high altitude. Its center temperature is lower than the surrounding, so it is called a "cold vortex." The corresponding typhoon, whose center temperature is higher than the periphery, is a warm vortex.

The vortex torrential rain is a torrential rain formed under the control of the cold vortex. The cold vortex occurs frequently in late spring and early summer in Inner Mongolia and Northeast China, and it often passes through or affects this area.

What are the characteristics of cold vortex rainstorm?

The vortex torrential weather is characterized by strong locality, decentralization, small rainfall drop, strong convection, and sometimes short-term heavy rainfall, so it is difficult to defend. In spite of the small amount of rain, it sometimes fell in a very short time, and it was also very provocative.

Not all cold vortex will rain!

Not every heavy vortex process is accompanied by heavy rain, which requires certain weather conditions.

After the cold vortex fell to the North China Plain, a relatively strong vortex system appeared at the lower level, which is what we call the low-level vortex system, namely the vortex. The high and low levels of coordination have only met the weather conditions caused by the heavy rain. The formation of vortexes is mainly related to the forced action of high altitude cold eddies and the topographic effects in North China. In addition, it is also related to the release of latent heat from precipitation.

After the formation of vortexes, the warm southwesterly airflow in its front part is very well transported. In addition, since the warm, moist air current is warm, the cold vortex is cold, and the cold and warm air are superimposed to form a warm structure that is cold and warm, which easily causes the atmosphere not to Stability, contributed to a better generation of atmospheric instability conditions. At the same time, there is a strong convergence of wind speed on the south and east side of the cold vortex, which triggers the occurrence of heavy rain. Based on these factors, heavy rain has emerged.

How can this defense against vortex torrential rain?

The rainfall process, especially the early weak cold air and the warm and humid air flow meet, the air convection is strong, and the rainfall is unevenly distributed, and the local short-term rainfall is strong, and may be accompanied by short-duly strong winds or hail. Therefore, we must pay attention to the disaster caused by heavy rainfall itself and the secondary disasters it brings.

During the rainfall, we must keep away from dangerous areas such as mountains, rivers, reservoirs, tourist attractions, and construction sites; we must guard against the possible geological disasters such as floods, mountain floods, mudslides, landslides, and collapses that may be induced by heavy rainfall in the mountains.

In addition, regardless of whether it is in the area of ​​coverage of rainfall forecast warnings, it is necessary to pay attention to forecasting and live information in a timely manner so as to prepare personnel and materials.

The information in this article comes from the Internet and was reorganized and edited by China Rescue Equipment Network.