How is the rainfall calculated?

According to the meteorological regulations:

If the rainfall is less than10.0mm in 24 hours, or less than 2.5mm in one hour, it is called light rain.

If the rainfall within 24 hours is less than 10.0~24.9 mm, or the rainfall within one hour is less than 2.6~8.0 mm, it is called moderate rain.

If the rainfall is less than 25.0~49.9 mm in 24 hours, or less than 8. 1~ 15.9 mm in one hour, it is called rainstorm.

When the rainfall within 24 hours is less than 50.0~99.9 mm, or the rainfall exceeds 16.0 mm, a rainstorm occurs. ..

According to the intensity of rainstorm, it can be divided into three types: rainstorm, heavy rainstorm and extremely heavy rainstorm.

Rainstorm: a rainfall process in which the precipitation is 30 ~ 70 mm in 12 hours or 50 ~ 100 mm in 24 hours.

Rainstorm:/kloc-the rainfall process with precipitation of 70 ~ 100~250mm in 0/2 hours or precipitation 100~250mm in 24 hours.

Extraordinary rainstorm: the rainfall process in which the precipitation is greater than140mm in 2 hours or 250mm in 24 hours.

Extended data

Rain usually occurs in four forms:

1, frontal rain (plum rain): Warm and humid air from the ocean meets cold air from the land. Because cold air is heavy and warm air is light, warm and humid air is forced to rise and condense when it is cold, forming a long and wide rain belt. This is frontal rain.

2. Convective rain: In summer, under the strong sunlight, the warm and humid air in some areas rises sharply, and it condenses when it meets cold to form rain. This is convective rain, which is called "thunderstorm" in meteorology, and we usually call it "explosion". In addition, typhoon rain is also a kind of convective rain.

3. Topographic precipitation: Warm and humid air from the ocean is forced to rise when it meets mountains, and condenses when it meets cold, resulting in rainfall.

4. Typhoon storm: The hot and humid air on the tropical ocean surface rotates and rises strongly in a large range. In the process of rising, the temperature drops rapidly, and a large amount of water vapor condenses into clouds and rain, which is typhoon rain.

References:

Baidu encyclopedia-rain