How is the wind level determined?

The strength of the wind is expressed by the wind speed, generally measured by the size of the wind or how many meters/second. There are thirteen grades:

Static wind: that is, level 0 wind.

Breeze: that is, level 4 wind. Wind with a wind speed of 5.5-7.9 m/s

Breeze: that is, level 3 wind.

Strong wind: that is, 8 winds. Wind with an average wind speed of17.2-20.7m/s.

Strong wind: 10 wind.

Storm: 1 1 wind. A wind with a wind speed of 28.5-32.6 m/s.

Hurricane: the wind above 12. (Tropical cyclones with the maximum surface wind force 12 or more near the center are called typhoons in the northwest Pacific).

Gust: a sudden change in instantaneous wind speed, sometimes accompanied by a change in wind direction, which lasts for a short time.

Black wind: a strong sandstorm weather with strong instantaneous wind speed and extremely low visibility.

Dry-hot wind: agricultural meteorological disaster weather with high temperature and low humidity and certain wind force.

Cold dew wind: Cold damage caused by cold air invasion in autumn, which reduces rice production.

Monsoon: the prevailing wind direction changes with the seasons, and it is almost the opposite within one year.

Trade wind: a large-scale airflow blowing from the south side of the subtropical high to the low-pressure area near the equator in the lower atmosphere.

Sea breeze: the wind blowing from the sea to the land in coastal areas due to the warming of the mainland surface during the day.

Land wind: In coastal areas, the surface wind blowing from the land to the sea due to the radiation cooling of the mainland at night.

Downburst: A strong downward airflow, usually causing scattered disastrous winds at or near the ground.

Wind shear: the spatial variation of wind vector in a specific direction.

Mountain wind: in mountainous areas, due to thermal reasons, the wind blowing from the hillside to the valley at night.

Valley wind: in mountainous areas, the wind blowing from the valley to the hillside during the day due to thermal reasons.

Gale: A sudden strong wind of short duration. Often accompanied by thunderstorms.

The wind power level is divided into six levels: wind speed 10.8~ 13.8 m/s, and the speed is 39~49 km/h. It is difficult to lift the umbrella, the branches are shaking and the wires are whirring. Grade 7: wind speed 13.9~ 17. 1 m/s, hourly speed 50~6 1 km. The whole tree is shaking, so it is inconvenient to walk in the wind. Grade 8: wind speed 17.2~20.7 m/s, speed 62~74 km/h. The branch is broken, and there is great resistance for people to advance. Grade 9: The wind speed is 20.8 ~ 24.4m/s and the speed is 75 ~ 88km/h, which blows down the straw house and roof tiles. 10 class: the wind speed is 24.5 ~ 28.4m/s and the speed is 89 ~ 102km/h, which can blow down trees and destroy ordinary buildings. 1 1 class: the wind speed is 28.5 ~ 32.6m/s, and the speed is103 ~17 km/h, which is destructive, knocking down trees and causing serious damage to general buildings. 12: the wind speed is greater than 32.6m/s and the hourly speed is greater than117km. The waves are huge and destructive.