Fu Lili: Why is it so difficult to forecast Taiwans ＂anemone＂ path

Source: China Science and Technology Daily

Author: Fu Lili

At present, the typhoon red warning continues.

According to the forecast of the Central Meteorological Observatory, around 3:30 pm on September 3, Typhoon No. 11 this year landed on the coast of Taitung City, Taiwan. The largest wind near the center was 15 (50 meters/second of 50 meters/second), The lowest air pressure in the center is 940 hundred Pache.The Central Meteorological Observatory predicts that the typhoon "Anemone" will be moved into the Taiwan Strait in the early morning of the 4th, and on the afternoon of the 5th, it will be available near the junction of Fujian, Guangdong. It is expected that the strength will be a strong tropical storm at the time of landing.

Although the typhoon that landed in Taiwan first before landing in Fujian also traced back to the typhoon "White Deer" in 2019.However, according to statistics, since 1949, the total number of typhoons in Fujian after landing in Taiwan has reached 68, including "Morak", "Yang Xi" and "Dragon King" and other impressive typhoons.

What are the characteristics of the second landing typhoon

At 11:45 pm on August 7, 2009, the typhoon "Morak" landed in Hualien, Taiwan. At 4:20 pm on August 9th, it landed again in Xiapu, Fujian.To.

Zhou Guanbo, chief forecast at the Typhoon and Marine Meteorological Forecast Center of the Central Meteorological Observatory, introduced that at that time, the typhoon "Swan", "Morak" and "Ai Tao" danced, the path forecast was very complicated.

After landing in Taiwan and then landing in Fujian and Guangdong, why is the path more difficult to predict?Zhou Guanbo explained that this is mainly because when the typhoon is close to Taiwan Island, because of the influence of the Central Mountains of Taiwan, it is often prone to inducing low pressure on the west side of the Taiwan Island, which leads to the dyingMake changes in the path, so it is often difficult to predict.

"However, due to the influence of the Central Mountains of Taiwan Island, the strength often weakened after typhoon landing in Taiwan. The strength will not be too strong when the second time landing on the coast of Fujian and Guangdong." Zhou Guanbo said that in addition to the narrow pipe effect of the Taiwan Strait, FujianThe coastal winds generally appear before landing in Taiwan, and when the typhoon landed in Fujian again, the wind was relatively small.

In addition, after the typhoon landed in Taiwan, it is generally affected by the dry air. It is easy to produce hollow typhoons. The intensity weakens significantly. The wind in the typhoon center is small, and the wind is large.

Zhou Guanbo said that at present, "Anemone" is slowly moving forward under a variety of forces. Not only does the path still have uncertainty, it may also lead to a long duration and strong intensity of heavy rainfall.Continue to pay attention to and prevent prevention.

Why do typhoons also like to get together

Not only the "anemone", according to the forecast of the Central Meteorological Observatory, Typhoon No. 9 "Sura" gradually weakened the intensity of the Beibu Bay Sea on the morning of the 3rd. In the Northwest Pacific Ocean, Typhoon "Hongyan" No. 12 has also been generated.

Why do typhoons like to get together? Is this phenomenon normal?

"In this season, it is not uncommon to coexist in multiple typhoons. There are multiple typhoons coexistence in various seas of the world.Nie Gaozhen said.

According to statistics, from 2000 to 2022, a total of 62 three typhoons coexist in the Northwest Pacific and the South China Sea, with an average of 2.7 times a year.Among them, 59 times appeared from July to October, the most in August, and September.

Nie Gaozhen pointed out that the coexistence of typhoons refers to a total of multiple tropical cyclone activities at a certain moment.Multi -typhoon activities usually occur in summer and autumn. At this time, it is the active season of typhoons. The conditions of marine thermal conditions and atmospheric power and thermal conditions are conducive to the generation and development of tropical cyclones, and multiple typhoon activities are prone to occur.

Nie Gaozhen explained that the typhoon mostly occurred in the tropical convergence zone. When the tropical convergence zone approached the equator, the typhoon was generated less; and when it advanced to the north, the typhoon activity became active.East -west direction, the southwest wind from the equator and the northeast wind from the north meet and converge here.On this east -west gap, multiple typhoons often generate or simultaneously generate.

When the subtropical high pressure is reduced, the typhoon on the east side is rapidly turned or going north by the subtropical high -voltage guidance. The typhoon on the west side loses the subtropical high -pressure guidance, and there will be stagnation and even deflection and mutual rotation south. At this time, the complexity of the typhoon path forecast willIt will increase sharply. The saddle field, the high pressure of the mainland, and the southwest monsoon may affect the typhoon path.When the typhoon generated in the tropical convergence zone coexist with the typhoon generated in other systems (east winds, etc.), due to different latitude, the situation of "three -legged" is easy to form.