How to distinguish between light rain, small to moderate rain, moderate rain, moderate to heavy rain, heavy rain and rainstorm?

When we listen to or watch the weather forecast, we often hear terms such as "light rain", "moderate rain" and "moderate to heavy rain", which are all grades of rainfall. Rainfall refers to the accumulation depth of rainwater falling on the ground without evaporation, infiltration and loss. The unit of depth stipulated in our country is millimeter. The level of rainfall is divided into light rain, moderate rain, heavy rain, heavy rain and heavy rain according to the amount of rainfall within 24 hours. It usually takes two minutes to completely wet the slate and roof tiles, and the puddle is slowly formed. Moderate rain: the rainfall is between 25mm, and rustling can be heard. Rain falls like a line, and raindrops are hard to separate. They splash slightly on holes in the roof and hard ground, and puddles quickly form. Heavy rain: The rainfall is between 25mm and 50mm. When it rains heavily, the rain falls like a downpour, and the raindrops splash on the roof tiles and hard ground for several inches. Rainstorms with rainfall exceeding 200 mm are called torrential rains, and low-lying areas are flooded. Shower: Shower, the raindrops are very heavy, falling and stopping, and the intensity changes dramatically. When it rains, it is dark, sometimes it suddenly becomes cheerful, revealing sunny days, and sometimes it is accompanied by thunder.

According to the regulations of China Meteorological Bureau, the rainfall within 24 hours is called daily rainfall. Where the daily rainfall is below 10 mm, it is called light rain, 10.24.9 mm is moderate rain, 25.49.9 mm is heavy rain, 50.99.9 mm is rainstorm, and 100.250.0 mm is rainstorm.

Because of China's vast territory, there is a great difference in precipitation between the east and the west and between the north and the south. According to the specific situation of this province, a few areas have formulated local standards for rainstorm. For example, in rainy Guangdong province, the daily rainfall exceeding 80 mm is called rainstorm; In Yan 'an, Shaanxi Province, where there is little rain, it is called rainstorm when the daily rainfall reaches more than 30 mm; The inland climate in Xinjiang is dry and there is little precipitation. Xinjiang Meteorological Bureau specially named rainy days with daily rainfall greater than or equal to 10 mm as "heavy precipitation".

The meteorological department calls it rain and snow precipitation, and precipitation is called precipitation. The unit of precipitation is usually mm.1mm. Precipitation means that the water depth per unit area is1mm. How much precipitation falls into the fields? As we know, the area per mu is 666.7 square meters. Therefore, the precipitation of 1mm is equivalent to an increase of 0.667 cubic meters of water per mu, and each cubic meter of water is 1000kg. In this way, the precipitation of 1mm is equivalent to pouring about 650kg of water per mu. According to the measurement, a rainfall of 5 mm can make dry land soak 3 cm ~ 3 cm. Light rain refers to the rain with precipitation less than10mm within 24 hours, ranging from 5mm to18mm,10mm to 25mm, moderate to heavy rain to18mm to 38mm, and heavy rain to rainstorm. The rainstorm exceeds 100 mm, and the rainstorm exceeds 200 mm. In weather forecast terms, different expressions have different meanings. For example, "sporadic light rain" means that the precipitation time is very short, and the precipitation does not exceed 0. 1 mm. "Sometimes there is light rain" means that the weather is cloudy and sometimes there is short-term precipitation. "Rainfall" refers to the beginning of precipitation in summer.

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