Why is it always raining recently? How is the rain formed?

In recent days, there have been strong convective weather and convective winds of thunderstorms in the north and south.

Cause of formation: Eurasia cold front goes south, and northwest Pacific warm wind goes north.

For example, the weather at 9 o'clock this morning: there is heavy rainfall in most parts of northern Inner Mongolia, Qinghai, Gansu, Ningxia, Shanxi, Hebei, Henan, Shandong, Sichuan, Chongqing, eastern Yunnan and Guangxi.

Rain is formed in three stages. First of all, the "raw material" of rain, that is, water vapor, takes off through the wind to form clouds, which form rain and fall to the ground.

The first stage, moving: the cloud is pushed by the wind in its position, that is, moving.

The second stage, combination: these small clouds driven by the wind are combined into larger new clouds in a certain field.

The third stage, accumulation: after the combination of small clouds, the upward gravity in large clouds increases. The upward gravity of the cloud center is stronger than that around it. These upward gravitational forces cause the clouds to expand vertically. Since then, the clouds have expanded upwards and gathered one by one. At the same time, it causes the cloud to expand to a relatively low temperature. So the water droplets and hail particles on the clouds began to increase. After the above stages, the weight of water droplets and hail particles increased, so that the upward gravity could not be supported. Finally, it fell from the clouds to the ground in the form of rain and hail.

I. Convective rain

When the air is heated strongly, the hot and humid air expands and rises, and the rain formed by the cooling and condensation of water vapor in the air is called convective rain. The equatorial region is dominated by convective rain all year round, and the convective rain in China is more common in summer afternoon.

Second, topographic precipitation.

Because the humid air was blocked by the mountain, the topographic precipitation was forced to climb along the hillside. In the process of rising, the water in the air cools and condenses to form precipitation. Mostly on windward slopes of high mountains.

Third, it's raining ahead.

When two different kinds of airflow meet, the interface between them is called front. On the front, warm, humid and lighter air is brought into cold, dry and heavier air. In the process of uplift, the water vapor in the air cools and condenses, and the precipitation formed is called frontal rain. Mostly in eastern China.

Fourth, typhoons and rain.

Rainstorms caused by typhoons, tropical storms and hurricanes.