What is the average critical wind speed? Wind speed, strength and direction. What is wind

Wind– this is horizontal movement (air flow parallel to earth's surface), resulting from uneven distribution of heat and atmospheric pressure and directed from the zone high pressure to the low pressure zone

Wind is characterized by speed (strength) and direction. Direction is determined by the sides of the horizon from which it blows, and is measured in degrees. Wind speed measured in meters per second and kilometers per hour. Wind strength is measured in points.

Wind in boots, m/s, km/h

Beaufort scale– a conventional scale for visual assessment and recording of wind force (speed) in points. Initially, it was developed by the English admiral Francis Beaufort in 1806 to determine the strength of the wind by the nature of its manifestation at sea. Since 1874, this classification has been adopted for widespread (on land and at sea) use in international synoptic practice. In subsequent years it changed and was refined (Table 2). A state of complete calm at sea was taken as zero points. Initially, the system was thirteen-point (0-12 bft, on the Beaufort scale). In 1946 the scale was increased to seventeen (0-17). The wind strength on the scale is determined by the interaction of the wind with various items. IN last years, the strength of the wind is most often assessed by speed, measured in meters per second - at the earth's surface, at a height of about 10 m above an open, flat surface.

The table shows Beaufort scale, adopted in 1963 by the World Meteorological Organization. The sea wave scale is nine-point (the parameters are given for a large sea area; in small water areas the waves are less). Descriptions of the action of moving air masses– given “for conditions earth's atmosphere near the earth's or water surface", with an air density of about 1.2 kg/m3 and above-zero temperatures. On the planet Mars, for example, the ratios will be different.

Wind strength in Beaufort scale and sea waves

Table 1
Points Verbal designation of wind force Wind speed,
m/s
Wind speed
km/h

Wind action

on the land

at sea (points, waves, characteristics, height and wavelength)

0 Calm 0-0,2 Less than 1 Complete absence wind. The smoke rises vertically, the leaves of the trees are motionless. 0. No excitement
Mirror smooth sea
1 Quiet 0,3-1,5 2-5 The smoke deviates slightly from the vertical direction, the leaves of the trees are motionless 1. Weak excitement.
There are light ripples on the sea, no foam on the ridges. Wave height is 0.1 m, length - 0.3 m.
2 Easy 1,6-3,3 6-11 You can feel the wind on your face, the leaves rustle faintly at times, the weather vane begins to move, 2. Low excitement
The ridges do not tip over and appear glassy. At sea, short waves are 0.3 m high and 1-2 m long.
3 Weak 3,4-5,4 12-19 Leaves and thin branches of trees with foliage continuously sway, light flags sway. The smoke seems to be licked from the top of the pipe (at a speed of more than 4 m/sec). 3. Slight excitement
Short, well defined waves. The ridges, overturning, form a glassy foam, and occasionally small white lambs are formed. The average wave height is 0.6-1 m, length – 6 m.
4 Moderate 5,5-7,9 20-28 The wind raises dust and pieces of paper. Thin branches of trees sway without leaves. The smoke mixes in the air, losing its shape. This is the best wind for operating a conventional wind generator (with a wind wheel diameter of 3-6 m) 4.Moderate excitement
The waves are elongated, white caps are visible in many places. Wave height is 1-1.5 m, length – 15 m.
Sufficient wind thrust for windsurfing (on a board under sail), with the ability to enter planing mode (with a wind of at least 6-7 m/s)
5 Fresh 8,0-10,7 29-38 Branches and thin tree trunks sway, the wind can be felt by hand. Pulls out big flags. Whistling in my ears. 4. Rough seas
The waves are well developed in length, but not very large; white caps are visible everywhere (in some cases, splashes form). Wave height 1.5-2 m, length – 30 m
6 Strong 10,8-13,8 39-49 Thick tree branches sway, thin trees bend, telegraph wires hum, umbrellas are difficult to use 5. Major disturbance
Large waves begin to form. White foamy ridges occupy large areas. Water dust is formed. Wave height - 2-3 m, length - 50 m
7 Strong 13,9-17,1 50-61 Tree trunks sway, large branches bend, it is difficult to walk against the wind. 6. Strong excitement
The waves pile up, the crests break off, the foam lies in stripes in the wind. Wave height up to 3-5 m, length – 70 m
8 Very
strong
17,2-20,7 62-74 Thin and dry branches of trees break, it is impossible to speak in the wind, it is very difficult to walk against the wind. 7. Very strong excitement
Moderately high, long waves. Spray begins to fly up along the edges of the ridges. Strips of foam lie in rows in the direction of the wind. Wave height 5-7 m, length – 100 m
9 Storm 20,8-24,4 75-88 Bend big trees, breaks large branches. The wind tears tiles off the roofs 8.Very strong excitement
High waves. The foam falls in wide dense stripes in the wind. The crests of the waves begin to capsize and crumble into spray, which impairs visibility. Wave height - 7-8 m, length - 150 m
10 Strong
storm
24,5-28,4 89-102 Rarely happens on land. Significant destruction of buildings, wind knocks down trees and uproots them 8.Very strong excitement
Very high waves with long, downward-curving crests. The resulting foam is blown away by the wind in large flakes in the form of thick white stripes. The surface of the sea is white with foam. The strong roar of the waves is like blows. Visibility is poor. Height - 8-11 m, length - 200 m
11 Cruel
storm
28,5-32,6 103-117 It is observed very rarely. Accompanied by great destruction over large areas. 9. Exceptionally high waves.
Small and medium-sized vessels are sometimes hidden from view. The sea is all covered with long white flakes of foam, located in the wind. The edges of the waves are blown into foam everywhere. Visibility is poor. Height - 11m, length 250m
12 Hurricane >32,6 >117 Devastating destruction. Individual wind gusts reach speeds of 50-60 m.s. Hurricane may happen before severe thunderstorm 9. Exceptional excitement
The air is filled with foam and spray. The sea is all covered with stripes of foam. Very poor visibility. Wave height >11m, length – 300m.

To make it easier to remember(compiled by: website author)

3 – Weak – 5 m/s (~20 km/h) – leaves and thin tree branches sway continuously
5 – Fresh – 10 m/s (~35 km/h) – pulls out large flags, whistles in ears
7 – Strong – 15 m/s (~55 km/h) – telegraph wires are humming, it’s difficult to go against the wind
9 – Storm – 25 m/s (90 km/h) – wind knocks down trees, destroys buildings

* Surface wind wavelength water bodies(rivers, seas, etc.) - the smallest horizontal distance between the tops of adjacent ridges.


Dictionary:

Breeze– weak onshore wind, with force up to 4 points.

Normal wind- acceptable, optimal for something. For example, for sport windsurfing, you need sufficient wind thrust (at least 6-7 meters per second), and for parachute jumping, on the contrary, it is better to have calm weather (excluding lateral drift, strong gusts near the earth’s surface and dragging of the canopy after landing).

Storm is called a long-lasting and stormy, up to a hurricane, wind with a force greater than 9 points (gradation on the Beaufort scale), accompanied by destruction on land and strong waves at sea (storm). Storms are: 1) squalls; 2) dusty (sandy); 3) dust-free; 4) snowy. Squalls begin suddenly and end just as quickly. Their actions are characterized by enormous destructive power (such wind destroys buildings and uproots trees). These storms are possible everywhere in the European part of Russia, both at sea and on land. In Russia, the northern border of the distribution of dust storms passes through Saratov, Samara, Ufa, Orenburg and the Altai mountains. Snow storms of great force occur on the plains of the European part and in the steppe part of Siberia. Storms are usually caused by the passage of an active atmospheric front, deep cyclone or tornado.

Squall– a strong and sharp gust of wind (Peak gusts) with a speed of 12 m/sec and above, usually accompanied by a thunderstorm. At a speed of more than 18-20 meters per second, gusty wind demolishes poorly secured structures, signs, and can break billboards and tree branches, cause power lines to break, which creates a danger for people and cars nearby. Gusty, squally wind occurs during the passage of an atmospheric front and with a rapid change in pressure in the baric system.

Vortex– atmospheric formation with rotational movement air around a vertical or inclined axis.

Hurricane(typhoon) is a wind of destructive force and considerable duration, the speed of which exceeds 120 km/h. A hurricane “lives,” that is, moves, usually for 9–12 days. Forecasters give it a name. The hurricane destroys buildings, uproots trees, demolishes light structures, breaks wires, and damages bridges and roads. Its destructive power can be compared to an earthquake. The homeland of hurricanes is the ocean, closer to the equator. Cyclones saturated with water vapor move from here to the west, more and more twisting and increasing speed. The diameters of these giant vortices are several hundred kilometers. Hurricanes are most active in August and September.
In Russia, hurricanes most often occur in the Primorsky and Khabarovsk territories, Sakhalin, Kamchatka, Chukotka, and the Kuril Islands.

Tornadoes– these are vertical vortices; squalls are often horizontal, part of the structure of cyclones.

The word "smerch" is Russian, and comes from the semantic concept of "twilight", that is, a gloomy, stormy situation. A tornado is a giant rotating funnel, inside of which there is low pressure, and any objects that are in the path of the tornado's movement are sucked into this funnel. As he approaches, a deafening roar is heard. A tornado moves above the ground at an average speed of 50–60 km/h. Tornadoes are short-lived. Some of them “live” for seconds or minutes, and only a few – up to half an hour.

On the North American continent, a tornado is called tornado, and in Europe – thrombus. A tornado can lift a car into the air, uproot trees, bend a bridge, and destroy the upper floors of buildings.

The Guinness Book of Records includes the tornado in Bangladesh, observed in 1989, as the most terrible and destructive in the entire history of observations. Despite the fact that residents of the city of Shaturia were warned in advance about the approach of the tornado, 1,300 people became its victims.

In Russia, tornadoes occur more often in summer months, in the Urals, Black Sea coast, in the Volga region and Siberia.

Forecasters classify hurricanes, storms and tornadoes as emergency events with a moderate speed of spread, so most often it is possible to issue a storm warning in time. It can be transmitted through civil defense channels: after the sound of sirens " Attention everyone!"You need to listen to local television and radio reports.


Symbols on weather maps for wind-related weather events

In meteorology and hydrometeorology, the direction of the wind (“where it blows from”) is indicated on the map in the form of an arrow, the type of plumage of which shows the average speed of air flow. In air navigation, the name of the direction is the opposite. In navigation on water, the unit of speed (knot) of a ship is taken to be equal to one nautical mile per hour (ten knots correspond to approximately five meters per second).

On a weather map, a long feather of a wind arrow means 5 m/s, a short one - 2.5 m/s, in the shape of a triangular flag - 25 m/s (follows a combination of four long lines and 1 short one). In the example shown in the figure, there is a wind of 7-8 m/s. If the wind direction is unstable, a cross is placed at the end of the arrow.

The picture shows symbols directions and wind speeds used on weather maps, as well as an example of applying icons and fragments from a hundred-cell matrix of weather symbols (for example, drifting snow and a snowstorm, when previously fallen snow rises and is redistributed in the ground layer of air).

These symbols can be seen on the synoptic map of the Hydrometeorological Center of Russia (http://meteoinfo.ru), compiled as a result of analysis of current data for the territory of Europe and Asia, which schematically shows the boundaries of warm and cold zones atmospheric fronts and the directions of their movements along the earth's surface.

What to do if there is a storm warning?

1. Close and secure all doors and windows tightly. Apply strips of plaster crosswise to the glass (to prevent fragments from scattering).

2. Prepare a supply of water and food, medicine, a flashlight, candles, a kerosene lamp, a battery-powered receiver, documents and money.

3. Turn off gas and electricity.

4. Remove items from balconies (yards) that could be blown away by the wind.

5. Move from light buildings to stronger ones or civil defense shelters.

6. In a village house, move to the most spacious and durable part of it, and best of all, to the basement.

8. If you have a car, try to drive as far as possible from the epicenter of the hurricane.

Children from kindergartens and schools must be sent home in advance. If a storm warning arrives too late, children should be placed in basements or central areas of buildings.

It is best to wait out a hurricane, tornado or storm in a shelter, a previously prepared shelter, or at least in a basement. However, often, a storm warning is given only a few minutes before the storm arrives, and during this time it is not always possible to get to shelter.

If you find yourself outside during a hurricane

2. You must not be on bridges, overpasses, overpasses, or in places where flammable and toxic substances are stored.

3. Hide under a bridge, reinforced concrete canopy, in a basement, cellar. You can lie down in a hole or any depression. Protect your eyes, mouth and nose from sand and soil.

4. You cannot climb onto the roof and hide in the attic.

5. If you are driving a car on the plain, stop, but do not leave the car. Close its doors and windows tightly. During snow storm Cover the engine from the radiator side with something. If the wind is not strong, you can shovel the snow from your car from time to time to avoid being buried under a thick layer of snow.

6. If you are in public transport, leave it immediately and seek shelter.

7. If the elements catch you in an elevated or open place, run (crawl) towards some kind of shelter (rocks, forest) that could dampen the force of the wind, but beware of falling branches and trees.

8. When the wind has died down, do not immediately leave the shelter, as the squall may recur in a few minutes.

9. Stay calm and don’t panic, help the victims.

How to behave after natural disasters

1. When leaving the shelter, look around to see if there are any overhanging objects, parts of structures, or broken wires.

2. Do not light gas or fire, do not turn on electricity until special services check the condition of communications.

3. Don't use the elevator.

4. Do not enter damaged buildings or go near downed electrical wires.

5. The adult population assists the rescuers.

Devices

The exact wind speed is determined using a device - an anemometer. If such a device does not exist, you can make a homemade wind measuring “Wild board” (Fig. 1), with sufficient measurement accuracy for wind speeds of up to ten meters per second.

Rice. 1. Homemade wind vane board Wilda:
1 – vertical tube (600 mm long) with a welded pointed upper end, 2 – front horizontal rod of the weather vane with a counterweight ball; 3 – weather vane impeller; 4 – upper frame; 5 – horizontal axis of the board hinge; 6 – wind measuring board (weighing 200 g). 7 – lower fixed vertical rod with cardinal direction indicators fixed on it, in eight directions: N – north, S – south, 3 – west, E – east, NW – northwest, NE – northeast, SE – southeast, SW – southwest; No. 1 – No. 8 - wind speed indicator pins.

The weather vane is installed at a height of 6 - 12 meters, above an open, flat surface. Under the weather vane there are arrows indicating the direction of the wind. Above the weather vane, to tube 1 on the horizontal axis 5, a wind measuring board 6 measuring 300x150 mm is hinged to frame 4. Board weight – 200 grams (adjusted using a reference device). Moving back from frame 4 is a segment of an arc attached to it (with a radius of 160 mm) with eight pins, of which four are long (140 mm each) and four are short (100 mm each). The angles at which they are fixed are with the vertical for pin No. 1-0°; No. 2 - 4°; No. 3 - 15.5°; No. 4 - 31°; No. 5 - 45.5°; No. 6 - 58°; No. 7 - 72°; No. 8-80.5°.
Wind speed is determined by measuring the angle of deflection of the board. Having determined the position of the wind measuring board between the pins of the arc, turn to the table. 1, where this position corresponds to a certain wind speed.
The position of the board between the pegs gives only a rough idea of ​​the wind speed, especially since the wind strength changes quickly and frequently. The board never remains in any one position for long, but constantly fluctuates within certain limits. By observing the changing slope of this board for 1 minute, its average slope is determined (calculated by averaging the maximum values) and only after that the average minute wind speed is judged. For high wind speeds exceeding 12-15 m/sec, the readings of this device have low accuracy (in this limitation - main drawback of the considered scheme)...


Application

average speed winds on the Beaufort scale different years its application

table 2

Point Verbal
characteristic
Average wind speed (m/s) according to recommendations
Simpson Köppen International Meteorological Committee
1906 1913 1939 1946 1963
0 Calm 0 0 0 0 0
1 Quiet wind 0,8 0,7 1,2 0,8 0,9
2 Light breeze 2,4 3,1 2,6 2,5 2,4
3 Light wind 4,3 4,8 4,3 4,4 4,4
4 Moderate wind 6,7 6,7 6,3 6,7 6,7
5 Fresh breeze 9,4 8,8 8,7 9,4 9,3
6 Strong wind 12,3 10,8 11,3 12,3 12,3
7 strong wind 15,5 12,7 13,9 15,5 15,5
8 Very strong wind 18,9 15,4 16,8 18,9 18,9
9 Storm 22,6 18,0 19,9 22,6 22,6
10 Heavy storm 26,4 21,0 23,4 26,4 26,4
11 Fierce Storm 30,0 27,1 30,6 30,5
12 Hurricane 29,0 33,0 32,7
13 39,0
14 44,0
15 49,0
16 54,0
17 59,0

The Hurricane Scale was developed by Herbert Saffir and Robert Simpson in the early 1920s to measure the potential damage of a hurricane. It is based on numerical values maximum speed wind and includes an assessment of storm surges in each of five categories. In Asian countries, this natural phenomenon is called a typhoon (translated from Chinese as “great wind”), and in Northern and South America- called a hurricane. When quantifying wind flow speed, the following abbreviations are used: km/h / mph– kilometers / miles per hour, m/s- meters per second.

table 3

Tornado scale

The tornado scale (Fujita-Pearson scale) was developed by Theodore Fujita to classify tornadoes by the degree of wind damage caused. Tornadoes are characteristic mainly of North America.

table 4

Category Speed,
km/h
Damage
F0 64-116 Destroys chimneys, damages tree crowns
F1 117-180 Tears prefabricated (panel) houses from the foundation or overturns them
F2 181-253 Significant destruction. Prefabricated houses are destroyed, trees are uprooted
F3 254-332 Destroys roofs and walls, scatters cars, overturns trucks
F4 333-419 Destroys fortified walls
F5 420-512 Lifts houses and moves them a considerable distance

Glossary of terms:

Leeward side object (protected from the wind by the object itself; area high blood pressure, due to the strong deceleration of the flow) is facing where the wind is blowing. In the picture - on the right. For example, on the water, small ships approach larger ships from their leeward side (where they are protected from waves and wind by the larger ship's hull). “Smoking” factories and enterprises should be located in relation to residential urban areas - on the leeward side (in the direction of the prevailing winds) and separated from these areas by sufficiently wide sanitary protection zones.


Windward side object (hill, sea vessel) - on the side from which the wind blows. On the windward side of the ridges, upward movements of air masses occur, and on the leeward side, a downward airfall occurs. The greatest part of precipitation (in the form of rain and snow), caused by the barrier effect of the mountains, falls on their windward side, and on the leeward side the collapse of colder and drier air begins.

In meteorology, when indicating the direction of the wind, the circle is divided into sixteen parts, according to 16-ray rose of rhumbs(after 22.5 degrees). For example, north-northeast is designated as NNE (the first letter is the main direction to which the bearing is closest). Four main directions: North, East, South, West.

Approximate calculation of dynamic wind pressure on square meter advertising board (perpendicular to the plane of the structure) installed near the roadway. In the example, the maximum storm wind speed expected in a given location is assumed to be 25 meters per second.

Calculations are carried out according to the formula:
P = 1/2 * (air density) * V^2 = 1/2 * 1.2 kg/m3 * 25^2 m/s = 375 N/m2 ~ 38 kilograms per square meter (kgf)

Notice that the pressure increases as the square of the speed. Take into account and include in the construction project sufficient margin of safety, stability (depending both on the height of the support post and on the critical angles of inclination of each specific pillar), resistance to strong gusts of wind and precipitation, in the form of snow and rain.

At what wind speed are plane flights canceled? civil aviation

The reason for disruption of flight schedules, delays or cancellations of flights may be storm warnings from weather forecasters at the departure and destination airfields.

The meteorological minimum required for the safe (normal) take-off and landing of an aircraft is the permissible limits for changes in a set of parameters: wind speed and direction, line of sight, condition of the airfield runway and the height of the lower cloud limit. Bad weather, in the form of intense atmospheric precipitation(rain, fog, snow and blizzard), with extensive frontal thunderstorms - can also cause the cancellation of flights from the airport.

The values ​​of meteorological minimums may vary for specific aircraft (according to their types and models) and airports (according to class and the availability of sufficient ground equipment, depending on the characteristics of the terrain surrounding the airfield and the available high mountains), and are also determined by the qualifications and flight experience of the crew pilots and the ship’s commander. The worst minimum is taken into account and for execution.

A flight ban is possible in case of bad weather at the destination airfield, if there are not two alternate airports nearby with acceptable weather conditions.

In strong winds, airplanes take off and land against the air flow (taxiing, for this purpose, to the appropriate runway). In this case, not only safety is ensured, but also the takeoff run distance and landing run distance are significantly reduced. Limitations on the lateral and tailwind components of wind speed, for most modern civil aircraft, are approximately 17-18 and 5 m/s, respectively. The danger of a large roll, drift and turn of an airliner during its takeoff and landing is represented by an unexpected and strong gusty wind (squall).


https://www.meteorf.ru – Roshydromet ( federal Service on hydrometeorology and monitoring environment). Hydrometeorological Research Center of the Russian Federation.

Www.meteoinfo.ru is the new website of the Hydrometeorological Center of the Russian Federation.

193.7.160.230/web/losev/osad.gif – Watch a video animation with a forecast synoptic weather map - precipitation, dynamics of cyclones and anticyclones for the coming days, showing horizontal movements of isobars (atmospheric pressure isolines) of the calculated weather model.

Www.ada.ru/Guns/ballistic/ wind/index.htm – For hunters about the effect of wind on the flight of a bullet, a ballistic calculator.

Directory ru.wikipedia.org/wiki/Climate_Moscow - metropolitan weather stations and statistical data on average monthly values ​​of the main weather parameters (temperature, wind speed, cloudiness, precipitation in the form of rain and snow), days when absolute temperature records were recorded, as well as the coldest and warm years in Moscow and the region.

Https://meteocenter.net/weather/ – Russian weather from the Meteorological Center.

Https:// www.ecomos.ru/kadr22/ postyMeteoMoskwaOblast.asp – Meteorological network (stations and posts) in the Moscow region. and in neighboring regions (Vladimir, Ivanovo, Kaluga, Kostroma, Ryazan, Smolensk, Tver, Tula and Yaroslavl regions)

Https:// www.ecomos.ru/kadr22/ sostojanieZagrOSnedelia.asp – environmental reports on the state of environmental pollution in Moscow (weather stations VDNKh, Balchug and Tushino) and the region over the past week.

Determining the strength, speed and direction of wind, visibility range, direction and speed of currents is extremely important when planning and executing dives in the open sea and coastal zones. Fighting the power of nature is pointless and sometimes extremely dangerous, so you should always take into account the influence natural phenomena factors such as current and wind when planning dives. The information below will help you evaluate the strength of some natural phenomena in order to take them into account when planning your dives.

Wind strength and speed.

Wind is the movement of air flow parallel to the earth's surface, resulting from uneven distribution of heat and atmospheric pressure, and directed from a high pressure zone to a low pressure zone.

The wind is characterized speed (force) And direction.Ndirection determined by the sides of the horizon and measured in degrees. Wind speed measured in meters per second and kilometers per hour. Wind power measured in points.

Beaufort scale - a conventional scale for visually determining and recording wind speed (force) in points. It was originally developed by the English admiral Francis Beaufort in 1806 to determine the strength of the wind by the nature of its manifestation at sea. Since 1874, it has been adopted for widespread (on land and at sea) use in international synoptic practice. In subsequent years it was changed and refined. A state of complete calm at sea was taken as zero points. Initially, the system was thirteen points (0-12). In 1946, the scale was increased to seventeen (0-17). The strength of the wind on the scale is determined by the interaction of the wind with various objects. In recent years, wind strength has more often been measured by its speed, measured in meters per second at the earth's surface, at a height of about 10 meters above an open, level surface.
Table 1 shows the Beaufort scale, adopted in 1963 by the World Meteorological Organization. The sea wave scale is nine-point (the wave parameters are given for a large sea area; in small water areas the waves are less). There are no instruments for measuring wave height, therefore the sea state in points is determined rather arbitrarily.

Wind strength in Beaufort scale and sea conditions.

Table 1

Points Verbal indication of wind force Wind speed Wind action
m/s km/h On the land At sea (points, waves, characteristics, height and wavelength)
0 Calm 0-0,2 less than 1 There is a complete absence of wind, smoke rises vertically, the leaves of the trees do not move. 0. There is no excitement.
Mirror-smooth sea, almost motionless. There may be haze over the surface of the water. The edge of the sea merges with the sky so that the border is not visible.
1 Quiet 0,3-1,5 2-5 The smoke deviates slightly from the vertical, the leaves of the trees are motionless. 1. Weak excitement.
There are slight ripples on the sea, the sea can still merge with the sky. Wave height up to 0.1 m, length 0.3 m.
2 Easy 1,6-3,3 6-11 You can feel the wind on your face, the leaves rustle faintly at times, and the weather vane begins to move. 2. Low excitement.
The ridges do not tip over and appear glassy. At sea there are short waves up to 0.3 m high and 1-2 m long.
3 Weak 3,4-5,4 12-19 Leaves and thin branches of trees with foliage continuously sway, light flags sway. The smoke seems to be licked from the top of the pipe (at a speed of more than 4 m/sec). 3. Slight excitement
Short, well defined waves. The ridges, overturning, form a glassy foam, and occasionally small white lambs are formed. The average wave height is up to 0.6 m, length - 6 m.
4 Moderate 5,5-7,9 20-28 The wind raises dust and pieces of paper. Thin branches of trees sway without leaves. The smoke mixes in the air, losing its shape. This is the best wind for operating a wind turbine. 4. Moderate excitement.
The waves are elongated, white caps are visible in many places. Wave height is 1-1.5 m, length up to 15 m.
5 Fresh 8,0-10,7 29-38 Branches and thin tree trunks sway, the wind can be felt by hand. Pulls out big flags. Whistling in my ears. 4. Rough seas.
The waves are well developed in length, but not very large; white caps are visible everywhere (in some cases, splashes form). Wave height is 1.5-2 m, length - 30 m.
6 Strong 10,8-13,8 39-49 Thick tree branches sway, thin trees bend, telegraph wires hum, umbrellas are difficult to use. 5. Major disturbance.
Large waves begin to form. White foamy ridges occupy large areas. Water dust is formed. Wave height is 2-3 m, length is 50 m.
7 Strong 13,9-17,1 50-61 Tree trunks sway, large branches bend, it is difficult to walk against the wind. 6. Strong excitement.
The waves pile up, the crests break off, the foam lies in stripes in the wind. Wave height is up to 3-5 m, length - 70 m.
8 Very strong 17,2-20,7 62-74 Thin and dry branches of trees break, it is impossible to speak in the wind, it is very difficult to walk against the wind. 7. Very strong excitement.
Moderately high, long waves. Spray begins to fly up along the edges of the ridges. Strips of foam lie in rows in the direction of the wind. Wave height is 5-7 m, length - 100 m.
9 Storm 20,8-24,4 75-88 Big trees bend, big branches break. The wind tears tiles off the roofs. 8. Very strong excitement.
High waves. The foam falls in wide dense stripes in the wind. The crests of the waves begin to capsize and crumble into spray, which impairs visibility. Wave height up to 10 m, length up to 150 m.
10 Heavy storm 24,5-28,4 89-102 Rarely happens on land. Significant destruction of buildings, the wind knocks down trees and uproots them. 8. Very strong excitement.
Very high waves with long, downward-curving crests. The resulting foam is blown away by the wind in large flakes in the form of thick white stripes. The surface of the sea is white with foam. The strong roar of the waves is like blows. Visibility is poor. Wave height is 8-11 m, length is 200 m.
11 Fierce Storm 28,5-32,6 103-117 It is observed very rarely. Accompanied by great destruction over large areas. 9. Exceptionally high waves.
Small and medium-sized vessels are sometimes hidden from view. The sea is all covered with long white flakes of foam, located downwind. The edges of the waves are blown into foam everywhere. Visibility is poor. Wave height up to 16 m, length up to 250 m.
12 Hurricane ≥32,7 more than 117 Devastating destruction. Individual wind gusts reach speeds of 50-60 m/sec. A hurricane can occur before a severe thunderstorm. 9. Exceptional excitement.
The air is filled with foam and spray. The sea is all covered with stripes of foam. Very poor visibility. Wave height >16 m, length - 300 m.

Visibility range scale.

Visibility- this is the maximum distance at which objects are detected during the day and navigation lights at night. Visibility is determined by the transparency of the atmosphere and depends on weather conditions and is characterized by visibility range. Below is a table for determining visibility range during daylight hours.

Distance Visibility characteristics
up to 1/4 cable up to 46 m Very poor visibility, thick fog or snowstorm.
up to 1 cable up to 185 m Poor visibility, thick fog or wet snow.
2-3 cables 370-550 m Poor visibility, fog, wet snow.
1/2 mile up to 1 km Haze, thick haze, snow.
1/2-1 mile 1-1.85 km Average visibility, snow or heavy rain.
1-2 miles 1.85-3.7 km Haze, haze or rain.
2-5 miles 3.7-9.5 km Light haze, haze, light rain.
5-11 miles 9.5-20 km Good visibility, the horizon is visible.
11-27 miles 20-50 km Very good visibility, the horizon is clearly visible.
over 27 miles more than 50 km Exceptional visibility, the horizon is visible very clearly, the air is transparent.

Wind is a horizontal flow of air that differs nearby certain characteristics: strength, direction and speed. It was to determine the speed of the winds that the Irish admiral back in early XIX century developed a special table. The so-called Beaufort scale is still used today. What is the scale? How to use it correctly? And what does the Beaufort scale not allow you to determine?

What is wind?

The scientific definition of this concept is as follows: wind is an air flow that moves parallel to the earth's surface from an area of ​​high to an area of ​​low atmospheric pressure. This phenomenon is characteristic not only of our planet. So, the strongest in solar system winds blow on Neptune and Saturn. And the earthly winds, in comparison with them, may seem like a light and very pleasant breeze.

The wind has always played an important role in human life. He inspired ancient writers to create mythical stories, legends and fairy tales. It was thanks to the wind that a person had the opportunity to overcome significant distances by sea (with the help of sailboats) and by air (by means of balloons). The wind is also involved in the “construction” of many earthly landscapes. Thus, it transports millions of grains of sand from place to place, thereby forming unique aeolian landforms: dunes, dunes and sand ridges.

At the same time, winds can not only create, but also destroy. Their gradient fluctuations can provoke a loss of control over the aircraft. Strong winds significantly expand the scale forest fires, and on large bodies of water it creates huge waves that destroy houses and kill people. This is why it is so important to study and measure wind.

Basic wind parameters

It is customary to distinguish four main parameters of wind: strength, speed, direction and duration. All of them are measured by special devices. The strength and speed of the wind are determined using a so-called anemometer, and the direction - using a weather vane.

Based on the duration parameter, meteorologists distinguish squalls, breezes, storms, hurricanes, typhoons and other types of winds. The direction of the wind is determined by the side of the horizon from which it blows. For convenience, they are abbreviated with the following Latin letters:

  • N (northern).
  • S (south).
  • W (western).
  • E (east).
  • C (calm).

Finally, wind speed is measured at a height of 10 meters using anemometers or special radars. Moreover, the duration of such measurements is different countries the world is not the same. For example, at American meteorological stations the average speed of air flows is taken into account in 1 minute, in India - in 3 minutes, and in many European countries- in 10 minutes. The classic tool for presenting data on wind speed and strength is the so-called Beaufort scale. How and when did it appear?

Who is Francis Beaufort?

Francis Beaufort (1774-1857) - Irish sailor, naval admiral and cartographer. He was born in the small town of An Uavy in Ireland. After graduating from school, the 12-year-old boy continued his studies under the leadership of the famous Professor Usher. During this period, he first showed extraordinary ability to study “ marine sciences" As a teenager he entered the service of the East India Company and took an active part in surveying the Java Sea.

It should be noted that Francis Beaufort grew up to be a rather brave and courageous guy. Thus, during the shipwreck in 1789, the young man showed great dedication. Having lost all his food and personal belongings, he managed to save the team's valuable instruments. In 1794, Beaufort took part in a naval battle against the French and heroically towed a ship that was hit by enemy fire.

Development of the wind scale

Francis Beaufort was extremely hardworking. Every day he woke up at five o'clock in the morning and immediately got to work. Beaufort was a significant authority among military men and sailors. However worldwide fame he acquired thanks to his unique development. While still a midshipman, the inquisitive young man kept a daily diary of weather observations. Later, all these observations helped him create a special wind scale. In 1838 it was officially approved by the British Admiralty.

One of the seas, an island in Antarctica, a river and a cape in northern Canada are named after the famous scientist and cartographer. Francis Beaufort also became famous for creating a polyalphabetic military cipher, which also received his name.

Beaufort scale and its features

The scale represents the earliest classification of winds according to their strength and speed. It was developed based on meteorological observations in conditions open sea. Initially, the classical Beaufort wind scale is twelve-point. Only in the middle of the twentieth century was it expanded to 17 levels so that hurricane-force winds could be distinguished.

Wind strength on the Beaufort scale is determined by two criteria:

  1. According to its effect on various ground objects and objects.
  2. According to the degree of roughness of the open sea.

It is important to note that the Beaufort scale does not allow you to determine the duration and direction of air flows. It contains a detailed classification of winds according to their strength and speed.

Beaufort scale: table for sushi

Below is a table with detailed description the effects of wind on ground objects and objects. The scale, developed by the Irish scientist F. Beaufort, consists of twelve levels (points).

Beaufort scale for sushi

Wind power

(in points)

Wind speed

The effect of wind on objects
0 0-0,2 Complete calm. Smoke rises vertically
1 0,3-1,5 The smoke deviates slightly to the side, but the weather vanes remain motionless
2 1,6-3,3 The leaves on the trees begin to rustle, the wind is felt on the skin of the face
3 3,4-5,4 Flags flutter, leaves and small branches sway on the trees
4 5,5-7,9 The wind lifts dust and small debris from the ground
5 8,0-10,7 You can “feel” the wind with your hands. Thin trunks of small trees sway.
6 10,8-13,8 Large branches sway, wires hum
7 13,9-17,1 Tree trunks sway
8 17,2-20,7 Tree branches break. It becomes very difficult to go against the wind
9 20,8-24,4 Wind destroys awnings and roofs of buildings
10 24,5-28,4 Significant damage, wind can tear trees out of the ground
11 28,5-32,6 Large destruction over large areas
12 more than 32.6Huge damage to houses and buildings. The wind destroys vegetation

Beaufort Table of Sea State

In oceanography there is such a thing as the state of the sea. It includes the height, frequency and strength of sea waves. Below is the Beaufort scale (table), which will help determine the strength and speed of the wind based on these signs.

F. Beaufort scale for open ocean

Wind power

(in points)

Wind speed

Effect of wind on the sea
0 0-1 The surface of the water mirror is perfectly flat and smooth
1 1-3 Small disturbances and ripples appear on the surface of the water
2 4-6 Short waves up to 30 cm in height appear
3 7-10 The waves are short, but clearly defined, with foam and “waddles”
4 11-16 Elongated waves up to 1.5 m in height appear
5 17-21 The waves are long with widespread “lambs”
6 22-27 Large waves with splashes and foamy crests form
7 28-33 Large waves up to 5 m high, foam falls in stripes
8 34-40 High and long waves with powerful spray (up to 7.5 m)
9 41-47 High (up to ten meters) waves are formed, the crests of which overturn and scatter with splashes
10 48-55 Very high waves that capsize with a strong roar. The entire surface of the sea is covered with white foam
11 56-63 The entire water surface is covered with long whitish flakes of foam. Visibility is significantly limited
12 over 64Hurricane. Visibility of objects is very poor. The air is oversaturated with spray and foam

Thus, thanks to the Beaufort scale, people can observe the wind and estimate its strength. This makes it possible to make the most accurate weather forecasts.

In 1963, the World Meteorological Organization clarified Beaufort scale and it was adopted to approximate the speed of wind from its effect on objects on land or from waves on the open sea. Average wind speed is indicated at a standard height of 10 meters above an open, level surface.

The smoke (from the captain's pipe) rises vertically, the leaves of the trees are motionless. Mirror smooth sea.

Wind 0 - 0.2m/s

The smoke deviates from the vertical direction, there are slight ripples in the sea, there is no foam on the ridges. Wave height up to 0.1 m.

You can feel the wind on your face, the leaves rustle, the weather vane begins to move, and there are short waves at sea with a maximum height of up to 0.3 m.

Wind 1.6 - 3.3 m/s.

The leaves and thin branches of the trees are swaying, light flags are swaying, there is a slight disturbance on the water, and occasionally small whitecaps form.

Average wave height 0.6 m. Wind 3.4 - 5.4 m/s.

The wind raises dust and pieces of paper; Thin tree branches are swaying, whitecaps on the sea are visible in many places.

Maximum wave height up to 1.5 m. Wind 5.5 - 7.9 m/s.

Branches and thin tree trunks sway, you can feel the wind with your hand, white lambs are visible everywhere.

Maximum wave height 2.5 m, average - 2 m. Wind 8.0 - 10.7 m/s.

In such weather we tried to leave Darlowo across the Baltic Sea. (Poland) against the wave. In 30 minutes only approx. 10km. and got very wet from the splashes. We were returning along the way - very good. funny.

Thick tree branches sway, thin trees bend, telephone wires hum, umbrellas are difficult to use; white foamy ridges occupy large areas, and water dust is formed. The maximum wave height is up to 4m, the average is 3m. Wind 10.8 - 13.8 m/s.

We encountered this kind of weather on boats in front of Rostock. The navigator was afraid to look around, the most valuable things were stuffed into his pockets, the walkie-talkie was tied to his vest. The splashes from the side waves constantly covered us. For a vodka-motor fleet, not to mention a simple motorboat, this is probably the maximum...

Tree trunks sway, large branches bend, it is difficult to walk against the wind, wave crests are torn off by the wind. The maximum wave height is up to 5.5 m. wind 13.9 - 17.1 m/s.

Thin and dry branches of trees break, it is impossible to speak in the wind, it is very difficult to walk against the wind. Strong seas.

Maximum wave height is up to 7.5 m, average - 5.5 m. Wind 17.2 - 20.7 m/s.

Large trees are bending, the wind is tearing tiles off the roofs, very rough seas, high waves. It is observed very rarely. Accompanied by destruction over large areas. The sea has exceptionally high waves ( maximum height- up to 16m, average - 11.5m), small vessels are sometimes hidden from view.

Wind 28.5 - 32.6 m/s. Fierce storm.

The sea is all covered with stripes of foam. The air is filled with foam and spray. Visibility is very poor. Complete f...c for small vessels, yachts and other ships - it’s better not to hit them.

Wind 32.7 m/s or more...

Beaufort scale- a conventional scale for visually assessing the strength (speed) of the wind in points based on its effect on ground objects or on sea waves. It was developed by the English admiral F. Beaufort in 1806 and at first was used only by him. In 1874, the Standing Committee of the First Meteorological Congress adopted the Beaufort scale for use in international synoptic practice. In subsequent years, the scale was changed and refined. The Beaufort scale is widely used in maritime navigation.

Wind strength at the earth's surface on the Beaufort scale
(at a standard height of 10 m above an open, level surface)

Beaufort points Verbal definition of wind force Wind speed, m/sec Wind action
on the land on the sea
0 Calm 0-0,2 Calm. Smoke rises vertically Mirror smooth sea
1 Quiet 0,3-1,5 The direction of the wind is noticeable from the drift of the smoke, but not from the weather vane. Ripples, no foam on the ridges
2 Easy 1,6-3,3 The movement of the wind is felt by the face, the leaves rustle, the weather vane is set in motion Short waves, crests do not capsize and appear glassy
3 Weak 3,4-5,4 The leaves and thin branches of the trees sway all the time, the wind flutters the upper flags Short, well defined waves. The ridges, overturning, form a glassy foam, occasionally small white lambs are formed
4 Moderate 5,5-7,9 The wind raises dust and pieces of paper and moves thin tree branches. The waves are elongated, white caps are visible in many places
5 Fresh 8,0-10,7 Thin tree trunks sway, waves with crests appear on the water Well developed in length, but not very large waves, white caps are visible everywhere (in some cases splashes are formed)
6 Strong 10,8-13,8 Thick tree branches sway, telegraph wires hum Large waves begin to form. White foamy ridges occupy large areas (splashes are likely)
7 Strong 13,9-17,1 The tree trunks are swaying, it’s difficult to walk against the wind The waves pile up, the crests break off, the foam lies in stripes in the wind
8 Very strong 17,2-20,7 The wind breaks tree branches, it is very difficult to walk against the wind Moderately high long waves. Spray begins to fly up along the edges of the ridges. Strips of foam lie in rows in the direction of the wind
9 Storm 20,8-24,4 Minor damage; the wind tears off smoke hoods and tiles High waves. The foam falls in wide dense stripes in the wind. The crests of the waves begin to capsize and crumble into spray, which impairs visibility
10 Heavy storm 24,5-28,4 Significant destruction of buildings, trees are uprooted. Rarely happens on land Very high waves with long, downward-curving crests. The resulting foam is blown away by the wind in large flakes in the form of thick white stripes. The surface of the sea is white with foam. The strong roar of the waves is like blows. Visibility is poor
11 Fierce Storm 28,5-32,6 Large destruction over a large area. Very rarely observed on land Exceptionally high waves. Small and medium-sized vessels are sometimes hidden from view. The sea is all covered with long white flakes of foam, located downwind. The edges of the waves are blown into foam everywhere. Visibility is poor
12 Hurricane 32.7 or more The air is filled with foam and spray. The sea is all covered with stripes of foam. Very poor visibility


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