What is the highest level of typhoon?

Typhoon is a strong tropical cyclone generated on the surface of tropical ocean. Typhoons are often accompanied by strong winds and heavy rains. The wind rotates counterclockwise. Isobars and isotherms are approximately a set of concentric circles. The central air pressure is the lowest and the temperature is the highest. ?

Typhoon classification. Typhoons are classified according to the maximum wind force near the center of tropical cyclones. In the past, the meteorological department of our country called the winds with the magnitude of 8 to 1 1 as typhoons, and the winds with the magnitude of 12 or above as strong typhoons. From1October 0989+65438+65438, the international unified classification method is adopted. The maximum wind force near the center is 8 ~ 9, and the maximum wind force near the center is 65438+ when 10 ~1. For the sake of simplicity, the following is still collectively referred to as typhoon.

Typhoon path. Typhoon paths can be roughly divided into three categories: ① westward movement: the typhoon moves from the east of the Philippines to the west, crosses the South China Sea, and finally lands on Hainan Island in China or northern Vietnam. (2) Landing type: The typhoon moved to the northwest, crossed the Taiwan Province Strait, landed in the coastal areas of Guangdong, Fujian and Zhejiang, and gradually weakened into a low pressure. This typhoon has the greatest impact on China. The two typhoons "90 15" and "97 1 1" which have had the greatest impact on Jiangsu in recent years belong to this type. (3) Parabolic type: The typhoon moves to the northwest first, then turns to the northeast when approaching the eastern coast of China, and turns to the vicinity of Japan, with a parabolic path. ?

Typhoon disaster. Typhoon is a very destructive and disastrous weather system, but sometimes it can also play a beneficial role in eliminating drought. Its harmfulness mainly includes three aspects: ① strong wind. The maximum wind force near the typhoon center is generally above 8. ② Heavy rain. Typhoon is one of the strongest rainstorm weather systems. Generally, it can produce rainfall of 150 mm ~ 300 mm in the area it passes through, and a few typhoons can produce torrential rain above1000 mm. The rainstorm caused by Typhoon No.3 1975 in the upper reaches of Huaihe River created the extreme value of rainstorm in Chinese mainland, forming the? "75.8"? Great flood. ③ Storm surge. Generally, typhoons will increase water in coastal waters, and the maximum water increase in coastal areas of Jiangsu Province can reach 3m. Typhoon "9608" and "97 1 1" increased water, which made Jiangsu's coastal areas along the Yangtze River have a super-historical climax. ?

After the typhoon is formed, it will generally move out of the source and experience the evolution process of development, weakening and extinction. A mature typhoon has a circular vortex radius of 500 km ~ 1000 km and a height of 15 km ~ 20 km. Typhoon consists of three parts: peripheral area, maximum wind speed area and typhoon eye. The wind speed in the peripheral area increases from outside to inside, with spiral clouds and precipitation; The strongest precipitation occurs in the maximum wind speed area, with an average width of 8 km ~ 19 km, and there is a circular cloud wall between it and the typhoon eye; The typhoon eye is located in the center of the typhoon. The most common typhoon eye is round or oval, ranging in diameter from 10 km to 70 km, with an average of about 45km. The weather in typhoon eye is calm, partly cloudy, dry and warm. ?

Typhoon number. China numbered the tropical depressions that entered the west of east longitude 150 degrees and the north latitude 10 degrees, and the maximum wind force near the center was greater than 8, and arranged them in the order of annual occurrence. This is the "Typhoon X this year (tropical storm, strong tropical storm)" that we heard or saw on radio and television.