Due to the tornado crossing the track of 14 line, the operation of the suburban section of 14 line was also affected, and no casualties were reported at present.
Tell me.
In the urban area, some damage caused by it, such as tents being blown down, trees falling down and even uprooting, is really dangerous if it is accidentally hit.
Risk. The formation of tornadoes often requires high convective available potential energy, low uplift and condensation height, high low-altitude humidity and strong wind shear.
Conditions.
1. At a high altitude of 200 hectopascals, Guangdong is located on the east side of the South Asian High, in the distributary area of the high-altitude westerly jet, with strong high-altitude radiation.
Dispersion promotes convergence movement at low altitude through suction. High-altitude divergence takes away the heat released by latent heat, which is also beneficial to convective wind.
Violence has been maintained and intensified. To sum up, Guangdong today does have sufficient conditions to support the occurrence of a deep moist convection.
But when it comes to sound analysis. Choose Hong Kong for sounding. It can be seen from the sounding in Hong Kong that almost the whole troposphere is wet and the water vapor conditions are quite excellent. There is a certain wind direction at low altitude.
It means that there is a warm advection (southwest monsoon) invasion. Because the southwest monsoon continues to provide energy, the effective potential of convection can reach above, indicating abundant thermal conditions. The southwest monsoon also brings low-level vertical wind shear, which is not too strong, but enough to support the transformation from horizontal vorticity to vertical vorticity, and also allows middle-level cyclones.
The structure is transmitted downward to a certain extent. In addition, the sounding shows that the low-altitude wet area is significant, the LCL height is only 600m, and so is the low-altitude high humidity.
It's really a big advantage of tornado landing.
2. On the whole, STP reaches 1. 1, which also indicates the potential possibility of tornado. It is worth noting that the wind field in the background environment of convective storm tends to strengthen before triggering, which means that convective cells are developing.
The vertical structure of the storm is strengthened, which brings stronger rising speed and mesoscale vertical wind shear, which is further conducive to the organized development of the storm.
The formation of supercells and the increase of low-level winds are more conducive to the landing of tornadoes. Due to the limited intensity of the tornado, it didn't leave too many marks on the radar. Before and after landing, the radar radial velocity map only shows the velocity.
The intensity of a mesocyclone with a shear of about 25m/s should be moderate, which can't meet the TVS standard required by China, that is, the short-range speed.
The degree shear is 45m/s, of course, this may be because of the resolution and the frequency interval of human body scanning. As the most developed city in China.
Guangzhou Guangzhou has a higher resolution phased array radar, which should be able to better predict the occurrence of this tornado.
Police.
Thirdly, the Pearl River Delta, or Guangdong as a whole, as the first stop of the southwest monsoon, has more typhoon activities, which are actually tornadoes in China.
In a high-incidence area, there are some tornadoes that are not very strong. In fact, there is no need to make a fuss and treat it with a normal heart.
Just, don't get too involved. This afternoon, I paid attention to the supercell located in Jiangsu: especially the supercell at the junction of Yancheng and Huai 'an, with very basic reflectivity.
Quite impressive. However, although a tornado warning was issued in Xiangshui, Jiangsu today, in fact, there should be no tornado grounded, just a warm area in Guangdong.
There is a tornado in the airflow system.
We can't see the existence of supercell in the radar reflectivity of Guangzhou, but the photos of Foshan netizens still show this CL (classic).
Typically, the supermonomer is different from HP high precipitation and LP low precipitation. Of course, this Foshan supercell should not be the system that caused the tornado in Taiping Town, Conghua District, Guangzhou.
This is a radar picture of a tornado:
It can be seen from the radar basic reflectivity and velocity map that the characteristics of tornado radar are not obvious, and there is no hook echo and high wind speed shear. However, according to the photos and videos from the scene, it can be judged that the power of this tornado is not small, and it is estimated that it has the level of EF 1, specifically.
The wind disaster has not spread, and it may cause the wind disaster of EF2 locally.
4. It can be seen from the 500hpa field that there is a trough from Hunan to Jiangxi, and the ground convergence in front of the trough accelerates the water vapor jet from the South China Sea to the north.
There is a high-intensity southwest jet at a height of 850 hectopascals in this area. There was a high-intensity warm and humid inflow near Guangzhou before and after, and it was excited after rising.
Thunderstorm clouds and supercells near Foshan are also formed in this way. Thunderstorm clouds near Conghua District in Guangzhou may be within a certain range.
In the case of vertical wind shear, tornadoes form and run aground. In fact, it can be recognized from a distance that it may also be a supercell, and the outline of the wall cloud and the middle cyclone can be seen. But ray
The reaction is really not obvious.
Five, actually, from the forecast, although the physical condition index is still very good, but STP (significant tornado
The index does not indicate the possibility of tornadoes, so the local tornadoes are unexpected.
It is understandable that the prediction and early warning of tornado is a world problem.
However, in the coming week, Guangdong and Guangxi are still within the scope of this jet stream, and it is necessary to continuously guard against the influence of strong convective weather. Tornado is a kind of strong convective weather, which is a small funnel-shaped airflow with violent rotation under unstable weather conditions.
Straight to the bottom of a severe thunderstorm.
The central wind can reach 50- 150m/s, and the width of tornadoes is usually between 50m- 1km, but there are some larger ones. The El Reno tornado in Oklahoma has a base width of 4.2 kilometers.