What weather system does the autumn rain in West China belong to?

Autumn rain in western China belongs to which of the following weather systems:

Autumn rain in western China is a special weather phenomenon of rainy autumn in western China.

Mainly refers to the autumn rain in Weishui River Basin, Hanshui River Basin, Chongqing, East Sichuan and East Sichuan. In autumn, the frequent southbound air meets the warm and humid air stranded in this area, which intensifies the frontal activity and produces long-term rainfall.

Among them, Sichuan basin, southwest Sichuan and western and northern Guizhou are the most common. The autumn rain in West China can last from September to around 165438+ 10, and the most notable feature is its long duration. The earliest appearance date can sometimes start from the end of August and end in the end of 165438+ 10 at the latest.

The autumn rain weather in western China is a quasi-frontal weather system with the characteristics of long duration, wide range and high precipitation intensity.

However, because the warm and humid air flow in autumn is usually not as good as that in midsummer, the rainfall intensity is not particularly large and lingering.

Continuous rainy weather with daily rainfall of more than or equal to 0. 1mm for five consecutive days is called autumn cotton rain. According to the duration of the process, it is divided into three grades: light lasting for 5-6 days, medium lasting for 7-9 days, and heavy lasting for more than 10 days.

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What caused the "Autumn Rain in West China"?

This is because the cold air that frequently goes south meets the warm and humid air that stays in autumn, resulting in frontal activity, thus forming long-term rainfall.

From the big climate background, the atmospheric circulation should be adjusted after autumn, the subtropical system will gradually weaken, and the westerly belt system will be obviously enhanced.

At this time, because the summer monsoon has not completely receded, the warm and humid air currents in the Bay of Bengal, the South China Sea and the western Pacific can still be continuously transported to the western part of China, resulting in continuous rainy weather.

Harm to crops

If you plant a millet in spring, you will reap 10 thousand seeds in autumn. Autumn is the season of harvest and sowing. If the weather is fine, it will bring a lot of convenience to harvesting and sowing. However, the continuous drizzle blocked the sunshine and brought low temperature, which was not conducive to the harvest and sowing of crops.

In case of "autumn rain", we should actively respond. It can strengthen the construction of farmland drainage facilities, timely drainage and waterlogging reduction, and reduce the impact of disasters.

Also pay attention to the weather change, sow after continuous rainy process to avoid rotten seeds.