Autumn is here, why is the typhoon so strong?

The typhoon "Plum Blossom", which is wrapped in continuous rainfall, has just passed, and the strong typhoon "Nanda Metropolis" will affect many places. At 6 o'clock on September 18th, due to the circulation of the periphery and cold air on the 14th of Typhoon No. 14. The Shandong Meteorological Observatory issued a blue warning of large yellow and inland winds on the sea. In people's impression, most of the typhoons happen in summer. Why is the typhoon so strong in autumn? What are the characteristics of the typhoon in this season?

What is autumn typhoon?

There is no strict definition of autumn typhoons. The typhoon generated from June to August is generally called a summer typhoon, and the typhoon generated from September to November is called Qiu Tingfeng. Many people think that the influence of typhoons in autumn is relatively small, but this is not the case. According to statistics, from 1949 to 2019, 226 super typhoons were generated in autumn, while only 149 were generated in summer, and the top 20 of typhoons were ranked in the top 20. And, the strongest strength is autumn typhoon. Whether it is the peak intensity of the quantity, the peak intensity of the typhoon, or the intensity of the landing intensity, the autumn typhoon is stronger than the summer typhoon.

Why is the typhoon so strong in the cold autumn?

Most of the autumn typhoons are generated in the northwest Pacific Ocean, which is far from the land. It has enough development space and time. Earlier, the ocean noodles had accumulated a lot of heat through the heating effect of the whole summer sun. In the early autumn, the sun -shot zone moved south to the south to heat the tropical ocean again, making the ocean calories reach its peak, so strong typhoons appeared at this time.

Compared with the typhoon in summer, the history of autumn typhoons is generally long, which is conducive to the development of typhoon intensity. In addition, in the autumn, typhoons have become smaller and smaller due to the South China Sea monsoon. Although the volume of typhoons is generally not too large, the typhoon structure is better and easy to develop.

During the influence of the autumn typhoon, cold air often participates in it, and the scope of wind and rain will have a greater effect. Although too strong cold air is not conducive to the strength of the typhoon, the strength of the cold air in early autumn is not too strong, which is increasing to the strength of the typhoon. It is particularly beneficial to the strength of the typhoon. In particular It is the cold air that is returning from East Road to increase the wind speed on the north side of the typhoon, which is a short -term development of the intensity of typhoons. As the cold air continues to be involved, the typhoon structure will change during the typhoon north, and it will gradually change from the heart -warming system to a cold -hearted system, and gradually become a green cyclone. But degeneration is not equal to weakening. Many typhoons will also produce strong wind and rain in the process of transsexuality, and due to the increased pressure of atmosphere during the transgender process, the variability cyclone often does not have a large average wind, but the gusts have a wide range of influence and strong intensity. During the autumn typhoon activity, the water vapor transportation conditions are often better. With the appropriate weather system configuration and the participation of cold air, a strong precipitation may also be produced on the periphery of the typhoon or far away. Strong, need to strengthen prevention. Compared with the typhoon generated in summer, the typhoon of autumn has three characteristics of the three major characteristics of the road, strong forces, and more serious losses.

Why is it difficult to predict the autumn typhoon path?

For forecasting, the changes in autumn typhoon paths and the predictions of landing locations are relatively greater than that of summer typhoons.

Under normal circumstances, the basic path that affects the typhoon in our country can be summarized as three categories: the first category is the westward path, the typhoon has been moved west to the west from the east of the Philippines, and the South my country Sea, South China coast and Hainan Island are landed; the second category For the northwest, move from the east of the Philippines to the northwest, crossing the Taiwan province and the Taiwan Strait in my country, and landing in Fujian and Guangdong. Or pass through the Ryukyu Islands and land on the coast of the river and Zhejiang; the third category is the steering path. The typhoon moved towards the northwest in the east of the Philippines, and then turned to the northeast, which is parabolic. This is the most common path. Typhoon can only move along the strong subtropical high -pressure periphery, while the autumn sub -height is weakened, so the movement path of the typhoon began to become elusive.

The autumn typhoon landing point is relatively south, mainly because after entering the autumn, the subtropical high pressure that affects the typhoon path began to retreat eastward, and the movement path of the typhoon was adjusted from the southern direction in the south of the summer.

There will be 2 to 3 typhoons in autumn or affect our country

Since the beginning of this year, the number of typhoons generated by the Northwest Pacific and South China Sea has a small number of typhoons, and the number of typhoons landing in my country is also small. Right now, the typhoon in summer has ended, and the autumn typhoon kicks off. It is expected that 2 to 3 typhoons will land or affect our country in autumn, which mainly affects the coastal areas of South China and the eastern coast. Statistics show that since September 6), 11 typhoons have been generated in the Northwest Pacific and South China Sea, which is 3.4 less than the same period (14.4) in the same year (14.4). Both landed in Guangdong), which is 2.2 less than the same period (5.2) in the same year (5.2).

This year, typhoons have five characteristics, namely, they have a small frequency, the number of login frequency is small, but the landing location is concentrated, the strength is weak, and the dual typhoon activities are difficult to predict the difficulty and extremely extreme.

It is estimated that in the fall of 2022, there are 8 to 10 tropical cyclones (central wind ≥8 levels) in the Northwest Pacific and South China Sea, which is less than the same period (11); 2 to 3 of them may significantly affect my country, which is close to our country, which is close to perennial year. In the same period (2.3). The main influence areas are South China and the coastal areas of the eastern part.

(Reporter Li Ling Wei Yuzhu)

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