How long does the rainy season last? If it keeps raining like this, I will collapse.

The middle and lower reaches of the Yangtze River in China are usually rainy from mid-June to early July every year. In the past few days, the sky has been gloomy and the precipitation has been constant, sometimes big and sometimes small. Therefore, there is a popular proverb in southern China:&; Uot rain hits Huangmeitou, and there is no sun for 45 days &; uot。 Continuous rain, high temperature and high humidity are the main characteristics of plum rain.

rainband

Although Meiyu is a unique weather and climate in the middle and lower reaches of the Yangtze River, its appearance is not isolated, but closely related to the north-south displacement of a large-scale rain belt.

In the eastern part of China east of E, during the flood season from mid-May to early June, the main rain belt swings in Nanling Mountains and its south area. In recent years, although it moved to the north of Nanling within a certain period of time, it often stayed in the south of 28N and 29° n from a waiting period (5 days) or the multi-year average of 10 days. This period is called &; Uot Jiangnan rainy season &; Uot or&; uot； Pre-flood season in South China &; uot。

In the middle and late June, the main rain belt moved northward within the range of 29° n-33° n (that is, Yichang in the west, the Yangtze River estuary in the east, and then across the sea to Japan; From the south of China Lake Basin to the south bank of Huaihe River), it is stable and less active. At this time, the area south of Nanling is outside the rain belt, and the rainy weather is over; The middle and lower reaches of the Yangtze River bid farewell to the sunny early summer and ushered in the rainy season. Heavy rain and rainstorm appeared from time to time and lasted until the beginning of July. This is a famous rainy season in the middle and lower reaches of the Yangtze River.

From mid-July, the rain belt moved northward again, reaching the area north of 33 N. Stagnation lingers in the Yellow River, Huaihe River Basin, North China, Northeast China and other places, causing heavy rainfall again and again, which is called & uot Huanghuai rainy season &; Uot, and. Uot rainy season in North China &; Uot At this time, the plum rains in the middle and lower reaches of the Yangtze River ended, the sun hung high and entered the hot summer season. This kind of weather will last until the end of August, and then the rain belt will quickly withdraw southward with the gradual activity of cold air. In less than a month, the rain belt will always retreat to the coastal areas of South China. The regular change of this rain belt shows that the plum rain in the middle and lower reaches of the Yangtze River is not an isolated and local weather and climate phenomenon, but an integral part of the main rainy season activities in eastern China, which is a reflection of the stagnation of the main rain belt in the middle and lower reaches of the Yangtze River during its northward movement.

Normal Meiyu and Abnormal Meiyu

Meiyu is a unique weather and climate phenomenon in the middle and lower reaches of the Yangtze River in early summer. It is the result of the stagnation of the Yangtze River basin during the northward movement of the main rain belt in eastern China. Meiyu is over and midsummer is coming. This seasonal change and rain belt change with the seasons, year after year, has formed a certain climate regularity. However, the annual plum rains are not completely consistent, and there are great interannual changes.

Meteorology, the beginning and ending time of plum rain is called &; Uot input Mei & amp； uot； (or&; Uot Li Mei uot) and&; Uot is the first beauty of uot (or&; Uot broken plums and uot). In the middle and lower reaches of the Yangtze River in China, plum blossoms in mid-June and in early July every year, lasting for more than 20 days. However, for each specific year, the beginning and end of meiyu and the intensity of meiyu are very different. As a result, plum rains are obvious in some years, not obvious in some years, and even empty plums appear. For example, the rainy season lasted for more than two months, which led to a rare waterlogging year in the middle and lower reaches of the Yangtze River. The rainy period is only two or three days a year, which is a rare dry year in history.

(1) Normal Meiyu:

The normal meiyu in the middle and lower reaches of the Yangtze River begins in mid-June and ends in mid-July, which means that it occurs within the two solar terms of&uot and&uot summer solstice uot. Meiyu period is about 20-30 days, and the rainfall is between-mm. Uot has a slight summer heat. From the beginning to the end, the main rainfall belt moved northward to the Yellow River and Huaihe River basins, and then moved to Shandong and North China. The Yangtze River basin began to change from rainy and humid weather to sunny and hot summer. According to statistics, this normal plum rain accounts for about half of the total.

(2) At the beginning of Meiyu:

In some years, the rainy season starts very early and suddenly comes at the end of May and the beginning of June. In meteorology,&; Meiyu that started before uot in uot awn is collectively referred to as&; Uot, it rains early. . The early plum rains will bring some abnormal phenomena. For example, since the cold air from north to south is still very frequent in the atmosphere near the ground at the beginning of the plum rain, the temperature is still relatively low and even a little chilly after the rainy day. An agricultural proverb says: uot eats Dragon Boat Festival brown and needs to be frozen three times &; That's what uot means; At the same time, there is no obvious damp phenomenon. Farmers in some areas in the middle and lower reaches of the Yangtze River call this section of Huang Meiyu with relatively low temperature & uot cold water Huangmei &; uot。 In the future, with the extension of rainy time and the strengthening of warm and humid air, the temperature will gradually increase, the humidity will continue to increase, and the inherent characteristics of Meiyu will become more and more obvious. The chance of early plum rain is roughly once in ten years. This kind of early plum rain often presents two situations. One is to start early and end late, even in late July. The rainy season lasts for forty or fifty days, and some years last for two months. The other is to start early and finish early. By the end of June, the middle and lower reaches of the Yangtze River entered midsummer. Due to the early arrival of midsummer, droughts of different degrees often occur in the middle and lower reaches of the Yangtze River.

(3) Late Meiyu:

Contrary to early plum rain, late plum rain is usually called late plum rain in meteorology. There are more opportunities for late meiyu than early meiyu. Because the solar term is already late, at the beginning of the late Meiyu, once the warm and humid air flows northward, its power is very strong, and the solar radiation is also relatively strong. When the air is heated, it is prone to strong convection, so there are often thunderstorms and showers in the later period of Meiyu. People also call this Huang Meiyu &; Uot Huangmei &; uot。 The duration of the late Meiyu is generally not long, with an average of only about half a month. However, the rainfall of this plum rain is sometimes quite concentrated.

(4) Special Meiyu:

In 2000, a once-in-a-century flood occurred in the Jianghuai Valley of China. The flood was caused by a particularly long plum rain. This year, there were many spring rains in the middle and lower reaches of the Yangtze River in the second half of May before the beginning of Meiyu. Meiyu came very early and began in early June. The weather has been rainy and rainy, with heavy rains and storms from time to time, which lasted for a very long time until the beginning of August. Uot, first beauty, uot. When the rainy weather ends and turns into midsummer weather, it is almost &; Uot, the beginning of autumn. Yes This year, the whole meiyu period lasted for two months, and with the spring rain in May, it reached more than two and a half months. Enter & uot； A slight summer heat. And. Uot summer heat and summer heat; It should always be sunny and hot in the middle and lower reaches of the Yangtze River in the future. Uot Futian uot But it's always cloudy and it's hard to see the sun. Pouring rain poured down on the ground from time to time, and floods rolled in many areas. Uot cold uot personal attack. In this year, the rainfall in the middle and lower reaches of the Yangtze River from May to July is generally-mm, which is close to the annual rainfall in normal years in this area. In some areas, the rainfall is as high as-millimeter, which is equivalent to one and a half years' rainfall in the same area, leading to flooding. China has a vast territory, and local floods often occur. Some may be caused by typhoon rainstorm, and some may be caused by several consecutive rainstorms brought by other weather systems, but their duration is not long, the flood recedes quickly, and the influence range is relatively small. Rainy days last for more than two months, causing basin-wide floods in the Yangtze River basin, which is extremely rare. This rare flood is often accompanied by abnormal plum rains. Like the flood in 2008, it was also caused by the extremely long plum rain.

(5) and uot short plums and uot and&uot empty plum uot:

Contrary to the exceptionally long plum rains, in some years, plum rains are very inconspicuous. It is like a passer-by, staying in the middle and lower reaches of the Yangtze River for ten days, and then going to journey to the south. Moreover, there is not much rain during this period, and it is rare to have one or two heavy rains. This situation is called &; Uot short plums and uot. What's more, there has been no continuous rainy weather in the Yangtze River basin since the early summer of some years. Most days are sunny, warm as spring, and very cool in the morning and evening. Uot Huangmei is dry and loose in season &; Uot weather Moldy clothes, which often happens in rainy season, almost never happen. As soon as the cool weather is over. Then it became midsummer. This year is called &; Uot empty plum uot & UOT's short-lived regret &; The average occurrence probability of uot and&uot empty plum uot in ten years is l-2 times. & uot short plums, UOT and&uot empty plums UOT frequently suffered from summer drought in 2008, and in some years, it also caused drought.

(6) pour Huangmei:

In some years, Huangmei days in the middle and lower reaches of the Yangtze River seem to have passed, the weather turned fine and the temperature rose, showing the characteristics of midsummer. However, a few days later, hot and humid thunderstorms and showers reappeared and remained for quite some time. This situation is like Huangmeitian returning to the middle and lower reaches of the Yangtze River, so it is called &; Uot pour Huangmei decoction; . & uo It thunders in summer, and Huangmei turns upside down &; uot。 This is a weather proverb widely circulated in the middle and lower reaches of the Yangtze River. It means after the rainy season, if&; Uot has a slight summer heat. When it thunders, the plum rain will reverse. There is some truth in this statement. Because after the meiyu, the weather in the middle and lower reaches of the Yangtze River is usually more and more stable, and thunderstorm is a symbol of weather instability. Besides, it's time &; Uot has a slight summer heat. Usually, cold air no longer affects the Yangtze River basin, and the occurrence of thunderstorms is often related to the southward movement of a small cold air in the north, which is conducive to the re-establishment of rain belts in the middle and lower reaches of the Yangtze River. Of course. Pour Huangmei decoction; It doesn't necessarily appear after thunder in a small summer. Generally speaking,&; Uot pour Huangmei decoction; Time is not long, ranging from about a week to ten days and a half months. But in&; Uot pour Huangmei decoction; During the period, due to many thunderstorms and showers, the rainfall is often quite concentrated, which needs attention. Due to&; Uot pour Huangmei decoction; It is a kind of plum rain, which usually turns into sunny and hot weather after it is over.

From the various plum rains described above, we can see that Huang Meiyu, which is usually considered to be similar, is actually diverse, and the differences between them are sometimes quite large. Take & uot input Mei & amp； uot； Generally speaking, the earliest is May 26th, and the latest is July 9th. & uot's first appearance in the United States was June 16 at the earliest and August 2 at the latest, with a difference of up to one and a half months. The longest rainy year lasts more than two months, which can cause rare floods, while the short year lasts only a few days, and some even appear &; Uot empty plum uot, bringing serious drought. It can be seen that plum rain is a complicated weather and climate phenomenon, which is far from what is stipulated in the lunar calendar. Uot input Mei & amp； uot； And. It's as simple as the first beauty of uot. Compared with normal meiyu,&; Uot jujube sister uot, and. Uot Chi Mei uot, and. Uot, a particularly long plum rain &; Uot, and. Uot empty plum uot and serious &; Uot pour Huangmei decoction; , all belong to abnormal Meiyu.