How to use signs to indicate the level of wind power? What about the wind direction?

Wind handle: indicates the direction of the wind, with 8 directions.

Wind feather: 3 or 4 short strokes and triangles indicate strong wind, perpendicular to the right side of the wind pole (northern hemisphere).

1- secondary: 1 vertical line 1 horizontal line

Grade 3-4: 1 vertical line and 2 horizontal lines

Layer 5-6: 1 vertical line 3 horizontal line

Grade 7-8: 1 vertical bar 4 horizontal bar.

Above level 8: 1 vertical bar 1 triangle is like a small flag.

Generally speaking, according to various phenomena caused by wind blowing on objects on the ground or water surface, the magnitude of wind power is divided into 18, with the smallest being 0 and the largest being 17.

Wind speed is the forward speed of the wind. The greater the air pressure difference between two adjacent places, the faster the air flow, the greater the wind speed and the greater the wind force. Therefore, the magnitude of wind is usually expressed by wind power. The unit of wind speed is meters per second or kilometers per hour. When the weather forecast is released, the wind level is mostly used.

Extended data:

In 200 1 year, the China Meteorological Bureau issued the Regulations on Typhoon Operation and Service, which added typhoons above 12 to 17 and adopted Beaufort scale. /typhoon kloc-0/2, set at 32.4-36.9 m/s; Grade 13 is 37.0-41.4m/s; 14 is 4 1.5-46. 1 m/s, 15 is 46.2-50.9 m/s, 16 is 51.0-56.

Typhoon Qionghai 30 years ago, the maximum wind force near the center was 73m/s, which exceeded the highest standard of 17. It's called 18, and it's also a common saying about super typhoon in the international maritime community.

The magnitude of wind speed is often expressed by several winds. The level of wind is determined according to the degree of influence of wind on ground objects. In meteorology, generally according to the size of the wind is divided into twelve levels:

Level 0 wind is also called no wind.

Level 2 wind is called breeze, the leaves are slightly noisy, and people feel windy.

Level 4 wind is called breeze, and the twigs of trees shake, which can blow up dust and paper on the ground.

The 6-level wind is called strong wind, the branches are shaking, the wires are whistling, and it is difficult to walk with an umbrella.

The 8-level wind is called strong wind, the twigs of trees can be broken, and people walk against the wind with great resistance.

10 wind is called gale, which is rare on land. Trees can be pulled up and buildings are seriously damaged.

Winds above 12 are called typhoons or hurricanes, which are extremely destructive and rarely seen on land.

In fact, in nature, the wind sometimes exceeds 12. For example, the central wind force of a strong typhoon or tornado may be much larger than the magnitude of 12, but the wind above the magnitude of 12 is rare, so the magnitude is generally not specified.

In the weather forecast, we often hear the expression "the north wind is 4 to 5", in which the wind refers to the average wind; If you hear the expression "gust 7", gust refers to the wind with high and low wind speed, and the wind at this time refers to the maximum wind force.

Wind speed refers to the horizontal distance of air flow per unit time. According to the phenomenon caused by the wind to the ground objects, the wind is divided into 13 grades, which are called wind grades.

The "East Wind Level 3" that people usually hear in the weather forecast refers to the "Beaufort Wind Level". "Beaufort Wind Scale" is a wind scale determined by Beaufort 1805 in Britain according to the degree of influence of wind on ground (or sea) objects, and * * * is divided into 0~ 17.

Due to the difference of wind speed, wind direction and humidity, many types of wind will be produced. Blast, gale, gale, gale, storm and hurricane, these common wind types, Beaufort wind force are seven, eight, nine, ten, eleven and twelve respectively.

Gust: When the air speed is high and low, the wind will be high and low, and there will be waves of feeling when blowing on people. This is a recognized gust of life.

Meteorology, wind speed usually refers to the average situation within 2 minutes, with high or low wind speed, and gust usually refers to the maximum instantaneous wind speed during this period. If the weather forecast, today's wind is 4-5, and the gust is 6, which means that today's average wind is 4-5, and the maximum instantaneous wind can reach 6.

Cyclone: It is a cyclone when the air flies in the air with dust to form a vortex.

Foehn: When the air crosses the ridge, it is easy to produce warm (or hot) dry wind on the leeward slope due to the sinking of the air, which is called Foehn.

Typhoon is an atmospheric vortex that occurs in the tropical ocean, so it is also called tropical cyclone. When the maximum wind force in the vortex center reaches more than 8, it is called typhoon; The maximum wind force in the center is 6-7, which is called weak typhoon; When the maximum wind force in the center reaches 8 to 12, it is called a strong typhoon.

Tornado: A small destructive vortex of air extending from cumulonimbus clouds to the ground. What happens on land is called tornado, and what happens on the ocean is called tornado, also called waterspout. Tornado is a violent storm with strong rotating force, and the maximum wind speed can reach more than 100 meters per second.

Mountain valley wind: In mountainous areas, the wind blows upward along the slopes and valleys during the day and downward along the slopes and valleys at night. This wind, which changes direction between hills and valleys alternately day and night, is called valley wind.

Sea-land wind: In coastal areas, the wind blows from the sea to the mainland during the day and from the land to the sea at night. This kind of wind that changes direction regularly day and night is called land-sea wind.

Glacier wind: shallow wind blowing down the mountain along the glacier during the day and night.

Monsoon: The prevailing wind direction changes regularly with the alternation of seasons. In winter, air flows from high-pressure land to low-pressure sea, which is called winter wind; In summer, the wind blows from the sea to the land, which is called summer monsoon. China is a country with remarkable monsoon, with northerly winds in winter and southerly winds in summer. This brings the monsoon climate characteristics of dry winter and wet summer to most parts of China.

Trade winds: persistent winds blowing from subtropical high to equatorial regions in the lower atmosphere. In the northern hemisphere, trade winds prevail in the northeast; In the southern hemisphere, it is in the southeast. Trade winds are characterized by a high degree of regularity, blowing in one direction with almost constant intensity all year round.

Anti-trade wind: the hot air rising from the equator flows in two layers in the upper atmosphere, which is called anti-trade wind. Because of the earth's rotation, the anti-trade winds are to the right in the northern hemisphere and to the left in the southern hemisphere. Anti-trade winds constantly bring the atmosphere to the latitude between 30 and 35, forming a state of air accumulation and forming a subtropical high pressure area. So there are more deserts in this area.

References:

Baidu Encyclopedia-Level of Wind