Why is there heavy rain in Guanzhong Plain in summer?

Causes of rainstorm in Guanzhong plain;

Weihe Plain has a continental climate, with an average annual temperature of 6 ~ 13℃ and an annual precipitation of 500 ~ 800 mm, of which 60% is from June to September, with short-term rainstorm, little precipitation in winter and spring, and frequent droughts in spring and summer.

Rainstorm: a heavy precipitation weather with 24-hour rainfall greater than or equal to 50 mm, 6-hour rainfall greater than or equal to 30 mm and 1 hour rainfall greater than or equal to 16 mm. ..

1. If the warm and humid airflow and cold air outside the subtropical high meet violently in July, August and September in central Shaanxi in summer and autumn, a large-scale disastrous rainstorm will be formed;

This kind of rainstorm weather may happen every year in Guanzhong Plain.

2. Sometimes it appears in convective cloud system or single convective cloud block, and belongs to mesoscale weather system-strong convective weather in meteorology. The horizontal scale of this weather is generally within 200 kilometers, and some are only a few kilometers. It is a disastrous weather with short duration, bad weather and strong destructiveness in meteorological disasters.

Strong convective weather is the accumulation of more water vapor on the ground. Because the specific gravity of water vapor is lighter than that of air, the specific gravity of hot and humid air mixed with air will be lighter than that of air, and the hot and humid air will float up to form a rising hot and humid airflow. When it rises to a certain height, due to the temperature drop, water vapor will condense into small water droplets to form clouds. At this time, its volume will soon be reduced to11244 of the original volume, forming a low pressure area. At this time, the area will attract air from all directions to supplement. Due to constant attraction, the hot and humid air on the ground will rotate and rise. Due to the centripetal force of rotating air, it will more strongly attract the cold air above and the hot and humid air below to meet, thus forming.

The Guanzhong Plain is prone to strong convective weather, but the scope is small and the impact is not too heavy.

3. The rainstorm brought by typhoon.

Typhoons rarely appear in Guanzhong Plain, and only typhoon "Dai Wen" will bring heavy rain when 1956 passes through Shaanxi.

This kind of rainstorm is rare in Guanzhong Plain for decades.

Three. History of rainstorm in Shaanxi;

Areas with frequent rainstorms every year in Shaanxi: Qinling Mountains in the south-central part of the province, Hanzhong, Ankang and Baoji, and mountainous areas in the south of Shangluo. Among them, southern Shaanxi is a rare rainstorm-prone area in China.

In Shaanxi, the rainstorm usually occurs in 6.7.8.9 month in southern Shaanxi, July, August and September in Guanzhong Plain and September in northern Shaanxi, 10. And it has the characteristics of "seven ups and eight downs".