What is the concept of precipitation of one thousand millimeters per hour?

A rainfall of 1,000 millimeters in one hour refers to extremely heavy rain.

The meteorological department calls rain and snow precipitation, and the amount of precipitation is called precipitation. The unit of precipitation is usually millimeters. 1 mm of precipitation refers to the water depth of 1 mm per unit area.

Light rain refers to rain with precipitation not exceeding 10 mm within 24 hours. Light to moderate rain is 5 mm to 18 mm, moderate rain is 10 mm to 25 mm, and moderate to heavy rain is 18 mm to 38 mm. mm, heavy rain is 25 mm to 50 mm, heavy rain is 38 mm to 75 mm. Rainfall exceeding 50 millimeters in 24 hours is called heavy rain, rain exceeding 100 millimeters is called heavy rainstorm, and rain exceeding 200 millimeters is called extremely heavy rain. ?

Extended information:

Precipitation factors:

1. Location: Mainly the location of sea and land affects precipitation. Usually the interior of the continent is dry and rainless.

2. Atmosphere: It mainly includes the influence of atmospheric circulation, fronts, cyclones (anticyclones) and other factors on precipitation.

3. Terrain: The windward slopes receive more precipitation, while the leeward slopes receive less precipitation; tall terrain will also prevent the entry of water vapor. For example, the dry climate in Xinjiang is not only due to the fact that it is deep inland, but also due to the surrounding high mountains that have a strong impact on water vapor. of obstruction.

4. Ocean currents: Warm currents have the effect of warming and humidifying the coastal climate; cold currents have the effect of cooling and dehumidifying the coastal climate.

5. Vegetation and hydrological conditions: In areas with high vegetation coverage and around lakes and reservoirs, the humidity of the air is higher and the relative precipitation is higher.

6. Human activities: The urban wet island effect means that there are many updrafts in the city that easily form clouds and cause rain; the rain island effect means that the city has a lot of dust, condensation nuclei, and more fog and low cloud specific effect areas.

Baidu Encyclopedia—Precipitation