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Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

author:Zhong Ming talked about science

Recently, many places in the south have ushered in a new round of rainfall, and it is expected that there will still be more rain in many places in the south in the coming week, of which the middle and lower reaches of the Yangtze River and some areas such as Yunnan and Guangxi will usher in heavy rainstorms, or even heavy rainstorms.

This round of rain lasts a long time, rainfall is large, and the rainy season is very similar, so the question is, is this round of rain really a new round of "plum rain"?

Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

(Source: Central Meteorological Observatory)

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Before we get to know about this round of rain, let's first understand how plum rains are formed.

We know that at about 30 degrees north and south latitude, there is a subtropical high pressure belt, and if the earth is all oceans, then the subtropical high pressure belt will circle the earth like a belt.

Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

However, due to the influence of the terrain, the real subtropical high pressure belt is not ring-shaped, but is cut into different small pieces, of which the deepest impact on China is the "West Pacific Subtropical High Pressure Belt", referred to as "West Pacific Subtropical High".

Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

There is also a cold air in the north, and every winter, the cold air force will strengthen, at which time they will go south to dominate, resulting in a drop in temperature in many parts of our country. As the sun's direct point of light continues to move north, the temperature in the northern hemisphere will continue to rise, and the western sub-high will gradually move west to the north, at which time the warm and humid air flow from the ocean will meet the cold air in the north near the north side of the subtropical high pressure ridge, forming rainfall.

Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

(Source: China Meteorological News Agency)

In this way, with the movement of subtropical high pressure, the location of China's rain belt is also constantly changing, of which the plum rain period refers to the late June to early July, the West Pacific Vice High continues to move north, resulting in cold air and warm and humid air flow in the middle and lower reaches of the Yangtze River converge, forming rainfall. Because it is the time when the plums are ripe, it is called "plum rain".

Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

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From the perspective of the formation reasons, this round of rainfall is because of the subtropical high pressure position, which is significantly southerly than in the previous period, resulting in warm and humid air flow from the ocean will meet with cold air in the middle and lower reaches of the Yangtze River in China, forming rainfall.

In addition, due to the equal force of cold and warm air, the rain belt moved slowly, so that it formed a long period of rain in the middle and lower reaches of the Yangtze River.

Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

Some experts believe that this round of rain is "inverted yellow plum". In fact, there is no clear standard for inverted yellow plum, which is a manifestation of climatic anomalies, generally occurring every 4-5 times.

In fact, this round of rainfall affects not only the middle and lower reaches of the Yangtze River, but also a strong precipitation process in South China, Yunnan, Guangxi and other places, and strong convective weather will occur in local areas.

Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

Central Meteorological Observatory

(Trivia: In the radar chart, the color blue means cloudy, green means drizzle, yellow to orange means moderate to heavy rain, red to purple means heavy to heavy rain, and purple means that there may also be natural disasters such as tornadoes and hail.) )

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Heavy rainfall lasts a long time and puts some pressure on local flood control.

In this round of rainfall process, there are more than 30 areas of rainfall in more than 50 mm, there are 10 areas of 24 hours of rainfall of more than 100 mm, according to the provisions of China Meteorological Observatory, 24 hours of precipitation of more than 50 mm is called heavy rain, of which 24 hours of precipitation in 100 mm -249.9 mm is called "heavy rainstorm", that is to say, 10 areas of China have rainfall reached the level of heavy rainstorm.

Pouring yellow plum is coming? The rain belt returns to the south, how long will the lingering rain last? Is this round of rain a new round of rain? Disaster prevention and mitigation

Heavy precipitation, coupled with a long duration of precipitation, will lead to saturation of soil moisture content, prone to water accumulation. Stagnant water will flow in the direction of lower terrain, and when the surrounding water is gathered in the same place, it is easy to form waterlogging in low-lying places.

It is precisely for this reason that people living in lower-lying areas should pay special attention to disaster prevention and mitigation, including but not limited to using flood control sandbags to raise doors and windows and transfer valuables to higher ground.

In addition, heavy precipitation may also cause secondary disasters such as mudslides and landslides in mountainous areas, and people living in mountainous areas should pay attention to prevention.

In addition, it should be noted that the mountainous terrain is steep, the water flow rate is too fast, and if the rainfall is too large, it is easy to form flash floods, so when the rainfall is large, it is best to stay away from the creek or near the river.

When the mountain torrent flows through the downstream plain area, the plain terrain is flat and the water flow rate is slow, if the rainfall time is long and the rainfall is large, it will increase the flood control pressure in the downstream area.

#Plum Rain##The Yangtze River Basin will now have sustained heavy rainfall ##湖北多地遭遇极端强降雨天气 #

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