What do the three raindrops represent?

Heavy rain, one raindrop represents light rain, two raindrops represent moderate rain, three raindrops represent heavy rain and four raindrops represent heavy rain.

According to the intensity of precipitation, China meteorological department usually divides rainfall into four grades:

(1) light rain: the rainfall within 24 hours is equal to or less than10mm. ..

(2) Moderate rain: the rainfall within 24 hours is between 10-25mm.

(3) Heavy rain: within 24 hours, the rainfall is between 25 and 50 millimeters.

(4) Rainstorm: the rainfall within 24 hours is greater than 50 mm ... If the rainfall within 24 hours is greater than 100 mm, it is a rainstorm. More than 200 mm is a torrential rain.

Formation process of rain

The water on the ground absorbs heat and turns into steam, which rises to the upper layer of the steam layer in the sky. Due to the low temperature of the upper steam layer, the steam volume decreases, the specific gravity increases and the steam decreases. Due to the high temperature below the steam layer, it absorbs heat during the falling process, rises again when it is cold, and then falls.

In this way, gas molecules gradually contract, and finally concentrate at the bottom of the steam layer, forming a low-temperature zone at the bottom, and water vapor concentrates in the low-temperature zone to form clouds. The cloud is getting bigger and bigger, the convection in the cloud is getting stronger and stronger, the temperature is getting lower and lower, and finally the raindrops fall.