Heavy rain, rainstorm and return peak must depend on the weather.

Heavy rain and rainstorm must depend on the weather at the peak of the return trip to deal with travel.

Heavy rain refers to rain with high precipitation intensity, which is often formed in cumulonimbus clouds. According to China's meteorological regulations, heavy rainfall with 24-hour precipitation exceeding 50 mm is called rainstorm. According to its precipitation intensity, it is divided into three grades, namely, the 24-hour precipitation is 50 to 99 mm, the rainstorm is between 100 and 249 mm, and the rainstorm is over 250 mm. However, due to the different precipitation and terrain characteristics, the standards of rainstorm and flood are different in different places.

In business practice, rainstorm can be divided into local rainstorm, regional rainstorm, large-scale rainstorm and extremely heavy rainstorm according to its occurrence and influence range. The local rainstorm lasts only a few hours or dozens of hours, generally affecting tens to thousands of square kilometers, causing less harm. However, when the rainfall intensity is particularly high, it will also cause serious casualties and property losses.

Brief introduction of rainstorm

The formation process of rainstorm is quite complicated. Generally speaking, sufficient and continuous water vapor, strong and lasting upward movement of airflow and instability of atmospheric structure are the main physical conditions for heavy rain. The favorable combination of weather system with different scales and underlying surface, especially topography, can produce heavy rain. The main weather systems that cause large-scale rainstorm in China are fronts, cyclones, shear lines, eddies, troughs, typhoons, easterly waves and intertropical convergence zone.

In addition, thermal thunderstorms will also cause short-term and small-scale heavy rains in arid and semi-arid areas. Rainstorms often fall from cumulonimbus clouds, and the condition for the formation of cumulonimbus clouds is that the atmosphere should contain enough water vapor. And there is a strong upward movement, which quickly transports water vapor upward. The water drop in the cloud is more and more affected by the upward movement. When the updraft supports it, it drops sharply to the ground.

Refer to the above content: Baidu Encyclopedia-Rainstorm