Why does it rain when the east wind blows?

Because in the eastern part of China, every heavy rainfall process is related to a low pressure process, it will be sultry. Low pressure, also known as "cyclone", originated in the western region and moved eastward, with a diameter of thousands of kilometers, mostly frontal rain. It's a fight between cold and warm air. Hot air climbs on top of cold air, cools, and water vapor condenses to produce precipitation. Precipitation mostly occurs on the cold air side.

The airflow in the low pressure moves counterclockwise around the center of the low pressure, so the front of the low pressure (that is, the east) is a warm and humid airflow from the southeast, which is lifted by the cold air in the north to form rainfall, while the back of the low pressure (that is, the west) is a dry and cold northwest airflow, and the weather turns fine.

Extended data:

If the east wind blows in summer, it will rain and there is no dry place on the ground. If the sky is covered with red clouds in summer, it will rain again and again The east wind is the ocean monsoon, which is warm and humid. But when the cold current is stronger than it, the west wind will rain and the east wind will stop.

A low pressure is formed on land, forming a southeast wind. Coupled with the influence of geostrophic deflection, the wind flows from high pressure to low pressure, and the low pressure is in the ocean in summer. In winter, on the contrary, the northwest wind is formed, and with the influence of geostrophic deflection, the wind blows from land to sea, forming high pressure on land and sea.

References:

People's Network-Today, the east wind blows in Beijing. On rainy days, citizens need to prepare rain gear when going out.