Typhoon Aulu has strengthened into a super typhoon. Hainan has issued a three-level typhoon warning. What preventive measures need to be taken?

Super Typhoon Oru is the third super typhoon Xuanlanno, Nanmadou, and Oru this year. It is also the third typhoon to have a Category 5 typhoon intensity Saffir Simpson scale. Currently The maximum wind force near the center is 62m/s with a two-minute average, which is above level 17. Typhoon Olu is still at its peak, W+MG

It is about to cross the Philippines and enter the South China Sea. Generally speaking, the friction between the land and the typhoon is fatal to the typhoon itself. Luzon, Philippines

The central and southern part of the island is where Typhoon Olu is about to pass. From the topographic map, you can see that the terrain is still very high. , there are mountains, and the cutting effect of mountains on the core clouds of typhoons is stronger than wind shear.

After Super Typhoon Olu hits the Philippines, its intensity will inevitably drop significantly. The path agencies in the South China Sea began to diverge.

According to numerical predictions, the western Pacific subtropical high pressure will expand westward starting today, and it will cover the Jiangnan and South China areas of my country.

This is like a cover to the north for Aolu. A pot cover was used to allow it to move westward along the southern part of the subtropical high, hit the Paracel Islands and land in Vietnam. But we need to know the fact that it has been a month since the last Typhoon Ma'an in the South China Sea. In this month, the South China Sea has accumulated considerable energy. From the sea temperature monitoring point of view, the South China Sea has There is an area in the middle with extremely high sea temperatures.

1. If Typhoon

develops beyond expectations in this area, it may approach southern Hainan and seriously affect the coast of Sanya and other places. The latent heat conditions in the South China Sea will have a negative impact on

Yu Aolu is also very good. In short, Sansha City, Sanya City and friends in Vietnam should pay attention. For the Philippines, a super typhoon will inevitably make a frontal landing.

It is inevitable. In the past, super typhoons that landed in the Philippines suffered heavy losses. Last year’s Rey, 2020’s Tiange, 2018’s Mangkhut, 2016’s Lotan, 2013’s Haiyan, etc. were all Super typhoons that land in the Philippines are also famous

disasters.

Friends in the coastal areas of Hainan and western Guangdong should pay attention to preventing strong winds and precipitation, and appropriately reduce going out during the next 26-28 days when Aolu is affected. In addition, this typhoon It will not land in our country, and the impact of strong winds, rainfall and storm surge will be relatively minor. However, although it did not land in our country, Olu was a very shocking typhoon. When Olu was first formed, almost all organizations underestimated the intensity of Olu. This is also a characteristic of small circulation typhoons: Easily and quickly burst into strength.

2. Olu is about to land in the Philippines and will also cross the mountains of the Philippines. Among them, it will cross the highest mountain range, with an altitude of nearly 2000m.

Mountains of this height are already vulnerable to typhoons. It has a greater weakening ability, and for a small circulation typhoon like Olu, the weakening effect of mountains on the typhoon is more severe than that of a large circulation typhoon. Olu is more likely to be unable to go out to sea. It remains at super typhoon level and may be downgraded to severe typhoon or typhoon level after heading out to sea. At present, the environmental vertical wind shear suffered by Aolu is weak, and the vertical wind shear in the northern part of the South China Sea is not too strong (wind shear is the difference in wind speed vectors between different layers. Environmental Larger wind shear is not conducive to the concentrated release of typhoon latent heat and interferes with the development of typhoons), and is conducive to the redevelopment of Olu

in the South China Sea.

3. The surface temperature of seawater in the South China Sea is at a very good level, much higher than the same period in normal years, which is also conducive to the re-

development of Aolu in the South China Sea. Generally, typhoons can develop when the sea temperature is above 26 degrees, and the sea temperature in the northern part of the South China Sea is even 31 degrees. Strong divergence can increase the inflow of the typhoon's bottom airflow, which is beneficial to the intensification of the typhoon. For Olu, due to the lack of high-altitude trough exploration at high levels, the divergence of the north side of Olu towards the pole is weak, which is a factor that is not conducive to its development. However, Olu moves towards the equator. The divergence of direction

is better, which is conducive to the development of Aolu. If Olu is severely worn by the terrain when it passes through the Philippines, its later development intensity may only be at the level of a strong typhoon. If the structural damage is relatively minor, it may reach the lower limit of super typhoon intensity.

From the perspective of its own structure, the Aolu circulation will expand to a certain extent, which means that the scope of influence of Aolu

will increase, mainly affecting Hainan, the western coast of Guangdong and other places , and Aulu, as a low pressure, will extract water vapor from Jiangnan and other places in the north, causing the drought to worsen. This is because Typhoon Oru is a low-pressure center. The existence of this low-pressure center will promote the strengthening of the southwest monsoon. Judging from the southwest monsoon monitoring index chart, the southwest monsoon will strengthen in the future and exceed normal levels. The average intensity green line is the southwest monsoon climate state

The average intensity. And we know that the southwest monsoon generally carries a large amount of water vapor. The strengthening of the southwest monsoon also means the strengthening of water vapor transport, which is conducive to the expansion of typhoon circulation.

4. However, in the Jiangnan area outside the scope of the typhoon's wind and rain, water vapor will be sucked away by the typhoon, causing the drought to a certain extent

Aggravated. Since this typhoon will not land in our country, its impact may not be as great as that of a typhoon or even a severe tropical storm landing in our country

However, certain preventive measures are also required. What really needs to be paid attention to is behind Olu.

A system of Dongting Lake and other places received some rain to alleviate the drought. Just go to the beach less often. This typhoon will not land in mainland China.