What will be the wind at 105 Beaufort. Beaufort scale - wind strength and sea conditions. Verbal definition of wind strength

Each natural phenomenon, which has different degrees of severity, is usually evaluated in accordance with certain criteria. Especially if information about it must be transmitted quickly and accurately. For wind strength, the Beaufort scale has become a single international benchmark.

Developed by the British rear admiral, a native of Ireland, Francis Beaufort (emphasis falls on the second syllable) in 1806, the system, improved in 1926 by adding information about the equivalence of wind strength in points of its specific speed, allows you to fully and accurately characterize this atmospheric process, while remaining relevant and to this day.

What is wind?

Wind is the movement of air masses parallel to the surface of the planet (horizontally above it). This mechanism is caused by pressure difference. The direction of movement always comes from the higher area.

To describe the wind, it is customary to use the following characteristics:

• speed (measured in meters per second, kilometers per hour, knots and points);
• wind strength (in points and m.s. - meters per second, the ratio is approximately 1:2);
• direction (according to cardinal directions).

The first two parameters are closely related. They can be mutually denoted by each other's units of measurement.

The direction of the wind is determined by the side of the world from where the movement began (from the north - the north wind, etc.). Velocity determines the pressure gradient.

Baric gradient (otherwise - barometric gradient) - change in atmospheric pressure per unit distance along the normal to a surface of equal pressure (isobaric surface) in the direction of decreasing pressure. In meteorology, the horizontal barometric gradient is usually used, that is, its horizontal component (Great Soviet Encyclopedia).

The speed and strength of the wind cannot be separated. A large difference in indicators between atmospheric pressure zones generates a strong and rapid movement of air masses above the earth's surface.

Features of wind measurement

In order to correctly correlate the data of meteorological services with your real position or to make a measurement correctly, you need to know what standard conditions professionals use.

• The measurement of the strength and speed of the wind takes place at a height of ten meters on an open flat surface.
• The name of the wind direction is given by the cardinal direction from which it blows.

Managers of water transport, as well as lovers of spending time in nature, often purchase anemometers that determine the speed, which is easy to correlate with the wind force in points. There are waterproof models. For convenience, devices of various compactness are produced.

In the Beaufort system, the description of the height of the waves, correlated with a certain force of wind in points, is given for the open sea. It will be much less in shallow water areas and coastal zones.

From personal to global use

Sir Francis Beaufort not only had a high military rank in the navy, but was also a successful practical scientist who held important posts, a hydrographer and cartographer, who brought great benefits to the country and the world. One of the seas in the Arctic Ocean, washing Canada and Alaska, bears his name. An Antarctic island is named after Beaufort.

A convenient system for estimating the strength of the wind in points, available for a fairly accurate determination of the severity of the phenomenon "by eye", Francis Beaufort created for his own use in 1805. The scale had a gradation from 0 to 12 points.

In 1838, the system of visual assessment of weather and wind strength in points began to be officially used by the British Navy. In 1874 it was adopted by the international synoptic community.

In the 20th century, several more improvements were made to the Beaufort scale - the ratio of points and a verbal description of the manifestation of the elements with wind speed (1926), and five more divisions were added - points for grading the strength of hurricanes (USA, 1955).

Criteria for estimating wind strength in Beaufort points

In its modern form, the Beaufort scale has several characteristics that allow, in combination, to most accurately correlate a specific atmospheric phenomenon with its indicators in points.

• First, it is verbal information. Verbal description of the weather.
• Average speed in meters per second, kilometers per hour and knots.
• The impact of moving air masses on characteristic objects on land and sea is determined by typical manifestations.

Non-dangerous wind

Safe wind is determined in the range from 0 to 4 points.

	Name	Wind speed (m/s)	Wind speed (km/h)		Description	Characteristic
	Calm, complete calm (Calm)		less than 1 km/h		Smoke movement - vertically upwards, tree leaves do not move	The surface of the sea is immovable, smooth
	Quiet wind (Light Air)				The smoke has a small angle of inclination, the weather vane is motionless	Light ripples without foam. Waves no higher than 10 centimeters
	Light Breeze				Feel the breath of the wind on the skin of the face, there is a movement and rustle of leaves, a slight movement of the weather vane	Short low waves (up to 30 centimeters) with a glass-like crest
	Weak (Gentle Breeze)				The continuous movement of foliage and thin branches on the trees, the waving of flags	Waves remain short but more noticeable. The ridges begin to tip over and turn into foam. Rare small "lambs" appear. The height of the waves reaches 90 centimeters, but on average does not exceed 60
	Moderate (Moderate Breeze)				Dust, small debris begins to rise from the ground	The waves become longer and rise up to one and a half meters. "Lambs" appear often

A wind of 5 points, characterized as "fresh", or fresh breeze, can be called borderline. Its speed ranges from 8 to 10.7 meters per second (29-38 km/h, or 17 to 21 knots). Thin trees sway along with the trunks. Waves rise up to 2.5 (average up to two) meters. Sometimes there are splashes.

Wind that brings trouble

With a wind force of 6 points, strong phenomena begin that can cause damage to health and property.

Points	Name	Wind speed (m/s)	Wind speed (km/h)	Wind speed (sea streaks)	Description	Characteristic
	Strong (Strong Breeze)				The thick branches of the trees sway strongly, the hum of telegraph wires is heard	Formation of large waves, foam crests acquire significant volume, splashing is likely. The average wave height is about three meters, the maximum reaches four
	Strong (Moderate gale)				The trees are swinging whole	Active movement of waves up to 5.5 meters high overlapping each other, foam dispersion along the wind direction
	Very strong (Gale)				Tree branches break from the pressure of the wind, it is difficult to walk against its direction	Waves of significant length and height: average - about 5.5 meters, maximum - 7.5 m. Moderately high long waves. Sprays fly up. Foam falls in stripes, the vector coincides with the direction of the wind
	Storm (Strong gale)				Wind damages buildings, begins to destroy roof tiles	Waves up to ten meters with an average height of up to seven. The streaks of foam become wider. Tilting combs splatter. Reduced visibility

Dangerous force of the wind

Wind force from ten to twelve points is dangerous and is characterized as a strong (storm) and severe storm (violent storm), as well as a hurricane (hurricane).

Wind uproots trees, damages buildings, destroys vegetation, destroys buildings. The waves make a deafening noise from 9 meters and above, long. At sea, they reach a dangerous height even for large ships - from nine meters and above. Foam covers the water surface, visibility is zero or close to such an indicator.

The speed of movement of air masses is from 24.5 meters per second (89 km / h) and reaches from 118 kilometers per hour with a wind force of 12 points. Violent storms and hurricanes (winds of magnitudes 11 and 12) are very rare.

Additional five points to the classical Beaufort scale

Since hurricanes are also not identical to each other in terms of intensity and degree of damage, in 1955 the United States Weather Bureau adopted an addition to the standard Beaufort classification in the form of five scale units. Wind strength from 13 to 17 points inclusive - these are clarifying characteristics for destructive hurricane winds and their accompanying environmental phenomena.

How to protect yourself when the elements are raging?

If the storm warning of the Ministry of Emergency Situations catches in an open area, it is better to follow the advice and reduce the risk of accidents.

First of all, you should pay attention to warnings every time - there is no guarantee that the atmospheric front will come to the area where you are, but you also cannot be sure that it will bypass it again. All items should be removed or securely fastened, to protect pets.

If a heavy wind catches in a fragile structure - a garden house or other light structures - it is better to close the windows from the air movement side, and if necessary, strengthen them with shutters or boards. On the leeward, on the contrary, slightly open and fix in this position. This will eliminate the danger of an explosive effect from the pressure difference.

It is important to remember that any strong wind can bring unwanted precipitation - in winter it is snowstorms and snowstorms, in summer dust and sand storms are possible. It should also be borne in mind that strong winds can occur even in absolutely clear weather.

Accepted for use in international synoptic practice. Initially, it did not indicate wind speed (added in 1926). In 1955, to distinguish between hurricane winds of varying strengths, the US Weather Bureau expanded the scale to 17.

It should be noted that the wave height in the scale is given for the open ocean, and not the coastal zone.

Beaufort points	Verbal definition of wind strength	Average wind speed, m/s	Average wind speed, km/h	Average wind speed, knots	wind action
					on the land	on the sea
0	Calm	0-0,2	< 1	0-1	Calm. The smoke rises vertically, the leaves of the trees are still	Mirror-smooth sea
1	Quiet	0,3-1,5	1-5	1-3	The direction of the wind is noticeable by the drift of the smoke, but not by the weather vane	Ripples, no foam on the crests of the waves. Wave height up to 0.1 m
2	Easy	1,6-3,3	6-11	3,5-6,4	The movement of the wind is felt by the face, the leaves rustle, the weather vane is set in motion	Short waves with a maximum height of up to 0.3 m, the crests do not tip over and appear glassy
3	Weak	3,4-5,4	12-19	6,6-10,1	Leaves and thin branches of trees are swaying all the time, the wind is waving light flags	Short, well defined waves. Combs, overturning, form vitreous foam. Occasionally, small lambs are formed. Average wave height 0.6 m
4	Moderate	5,5-7,9	20-28	10,3-14,4	The wind raises dust and debris, sets in motion the thin branches of trees	The waves are elongated, the lambs are visible in many places. Maximum wave height up to 1.5 m
5	Fresh	8,0-10,7	29-38	14,6-19,0	Thin tree trunks sway, the movement of the wind is felt by hand	Well developed in length, but not large waves, the maximum wave height is 2.5 m, the average is 2 m. White lambs are visible everywhere (splashes form in some cases)
6	Strong	10,8-13,8	39-49	19,2-24,1	Thick tree branches sway, telegraph wires hum	Large waves begin to form. White foamy ridges occupy large areas, splashing is likely. Maximum wave height - up to 4 m, average - 3 m
7	Strong	13,9-17,1	50-61	24,3-29,5	Tree trunks sway	The waves pile up, the crests of the waves break, the foam falls in strips in the wind. Maximum wave height up to 5.5 m
8	Very strong	17,2-20,7	62-74	29,7-35,4	The wind breaks the branches of trees, it is very difficult to go against the wind	Moderately high long waves. On the edges of the ridges, spray begins to take off. Stripes of foam lie in rows in the direction of the wind. Maximum wave height up to 7.5 m, average - 5.5 m
9	Storm	20,8-24,4	75-88	35,6-41,8	Minor damage, the wind begins to destroy the roofs of buildings	High waves (maximum height - 10 m, average - 7 m). Foam in wide dense stripes lays down in the wind. The crests of the waves begin to capsize and crumble into spray that impair visibility.
10	Heavy storm	24,5-28,4	89-102	42,0-48,8	Significant destruction of buildings, the wind uproots trees	Very high waves (maximum height - 12.5 m, average - 9 m) with long crests curving down. The resulting foam is blown 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
11	Violent storm	28,5-32,6	103-117	49,0-56,3	Large destruction over a large area. It is observed very rarely.	Visibility is poor. Exceptionally high waves (maximum height - up to 16 m, average - 11.5 m). Small to medium sized boats are sometimes out of sight. The sea is all covered with long white flakes of foam, which are located in the wind. The edges of the waves are everywhere blown into foam
12	Hurricane	> 32,6	> 117	> 56	Huge destruction, the building, structure and houses were seriously damaged, trees were uprooted, vegetation was destroyed. The case is very rare.	Exceptionally poor visibility. The air is filled with foam and spray. The sea is covered with strips of foam
13
14
15
16
17

see also

Links

• Description of the Beaufort scale with photographs of the state of the sea surface.

Wikimedia Foundation. 2010 .

See what the "Beaufort Scale" is in other dictionaries:

- (Beaufort scale) at the beginning of the 19th century. the English admiral Beaufort proposed to determine the strength of the wind by the windage that at the time of observation the given ship itself or other sailing ships in its visibility can carry, and evaluate this strength by scale points, ... ... Marine Dictionary

Conditional scale for visual assessment of the strength (speed) of the wind, based on its impact on ground objects or on the water surface. It is mainly used for ship observations. Has 12 points: 0 calm (0 0.2 m / s), 4 moderate ... ... Emergencies Dictionary

Beaufort scale- The scale for determining the strength of the wind, based on a visual assessment of the state of the sea, is expressed in points from 0 to 12 ... Geography Dictionary

Beaufort scale- 3.33 Beaufort scale: A twelve-point scale adopted by the World Meteorological Organization for the approximate estimation of wind speed from its effect on ground objects or from waves on the high seas. Source … Dictionary-reference book of terms of normative and technical documentation

A scale for determining the strength of the wind by visual assessment, based on the effect of the wind on the state of the sea or on land objects (trees, buildings, etc.). It is mainly used for observations from ships. Adopted in 1963 by the World ... ... Geographic Encyclopedia

BEAUFORT SCALE- a conditional scale in points in the form of a table for expressing the speed (strength) of the wind by its action on ground objects, by sea waves and the ability of the wind to set sailing ships in motion. The scale was proposed in 1805-1806. British Admiral F. ... ... Wind Dictionary

BEAUFORT SCALE- wind force estimation system. It was proposed by the English hydrographer F. Beaufort in 1806. It is based on the visual perception of the action of the wind on the water surface, smoke, flags, ship superstructures, on the shore, structures. The assessment is made in points ... ... Marine encyclopedic reference book

Beaufort scale- a conditional scale in points from 0 to 12 for visual assessment of the force (speed) of the wind in points by sea waves or by the action of ground objects: 0 shtnl (calmness 0 0.2 m / s); 4 moderate wind (5.5 7.9 m/s); 6 strong wind (10.8 13.8 m/s); nine… … Dictionary of military terms

BEAUFORT SCALE- In damage management: conditional scale for visual assessment and recording of wind strength (speed) in points or waves at sea. It was developed and proposed by the English admiral Francis Beaufort in 1806. Since 1874, it has been adopted for use in ... ... Insurance and risk management. Terminological dictionary

The Beaufort scale is a twelve-point scale adopted by the World Meteorological Organization for an approximate estimate of wind speed by its effect on ground objects or by waves on the high seas. The average wind speed is indicated on ... ... Wikipedia

Beaufort scale - a conditional scale that allows you to visually assess the approximate strength of the wind by its effect on ground objects or by waves at sea. Developed by the English admiral and hydrographer Francis Beaufort (Eng. Francis Beaufort) in 1806.

Since 1874, it has been officially accepted for use in international synoptic practice. Since 1926, the Beaufort scale has additionally indicated wind strength in meters per second at a height of 10 meters from the surface. In the USA, in addition to the international 12-point scale, since 1955, a scale expanded to 17 points has been used, which is used for more accurate gradation of hurricane winds.

Strength and average wind speed				Verbal definition	Manifestation on land	Manifestation at sea	Approximate wave height, m	visual manifestation
Beaufort points	meters per second	kilometers per hour	nodes
0	0-0,2	0,0-0,7	0-1	Calm	The smoke rises vertically or almost vertically, the leaves of the trees are motionless.	Mirror-smooth water surface.	0
1	0,3-1,5	1,1-5,4	1-3	Quiet wind	The smoke deviates from the vertical direction, the weather vane does not rotate and does not turn	Light ripples on the sea, no foam on the crests of the waves.	0,1
2	1,6-3,3	5,8-11,9	4-6	Light breeze	The movement of the wind is felt by the face, the leaves rustle, the movement of the weather vane is observed	Short waves with a vitreous crest, do not tip over when moving.	0,3
3	3,4-5,4	12,2-19,4	7-10	weak wind	Flags and leaves sway.	Short waves with clearly defined boundaries, wave crests form foam when capsizing, white caps appear on individual waves.	0,6
4	5,5-7,9	19,8-28,4	11-16	moderate wind	The wind raises dust, light debris. Leaves and thin branches are constantly in motion.	Waves are elongated, light lambs appear everywhere	1,5
5	8,0-10,7	28,8-38,5	17-21	Fresh breeze	Branches and thin trunks of trees sway, bushes sway. The wind is felt by hand.	Not very large waves, lambs are visible everywhere.	2,0
6	10,8-13,8	38,9-49,7	22-27	Strong wind	Thin branches bend, thick branches of trees sway, the wind hums in the wires.	Over the entire surface, waves are visible, from the foamy crests of which spray breaks. Sailing in light boats is not safe.	3,0
7	13,9-17,1	50,1-61,6	28-33	strong wind	Trunks and thick branches of trees sway. It is difficult to go against the wind.	Waves pile up, crests break, covered with foam. Navigation on light motor boats is not possible.	4,5
8	17,2-20,7	61,9-74,5	34-40	Very strong wind	The wind breaks the dry branches of trees, it is very difficult to go against the wind, it is impossible to talk without shouting.	High long waves with splashes. Rows of foam fall in the direction of the wind.	5,5
9	20,8-24,4	74,9-87,8	41-47	Storm	Large trees bend and break, light roofs are torn off the roofs.	High waves with rows of foam. The spray obstructs visibility.	7,0
10	24,5-28,4	88,2-102,2	48-55	Heavy storm	Trees are uprooted, individual buildings are destroyed. It's impossible to go.	Very high waves with crests bent down. The surface of the water is covered with foam, small boats disappear from view behind the waves.	9,0
11	28,5-32,6	102,6-117,4	56-63	Violent storm	Catastrophic destruction of light structures, uprooting of trees.	High waves covered with flakes of white foam. Medium ships are out of sight.	11,5
12	>32,6	>117,4	>63	Hurricane	The destruction of stone buildings, the complete destruction of vegetation.	Loss of visibility due to spray, water surface covered with foam. Destruction of light ships.	12,0

Wind is a horizontal flow of air that has a number of specific characteristics: strength, direction and speed. It was to determine the speed of the winds that the Irish admiral developed a special table at the beginning of the 19th century. The so-called Beaufort scale is still used today. What is a 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 typical not only for our planet. Thus, the strongest winds in the solar system blow on Neptune and Saturn. And the terrestrial 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 is thanks to the wind that a person has 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 "building" of many earthly landscapes. So, it transfers millions of grains of sand from place to place, thereby forming unique eolian landforms: dunes, dunes and sandy 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. A strong wind significantly expands the scale of forest fires, and on large reservoirs it gives rise to huge waves that destroy houses and claim the lives of people. That is why it is so important to study and measure the wind.

Basic wind parameters

It is customary to distinguish four main wind parameters: strength, speed, direction and duration. All of them are measured using special devices. The strength and speed of the wind is determined using the so-called anemometer, the direction - with the help of 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 (southern).
• W (western).
• E (eastern).
• C (calm).

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

Who is Francis Beaufort?

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

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

Development of the wind scale

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

In honor of the famous scientist and cartographer, one of the seas, an island in Antarctica, a river and a cape in northern Canada are named. And Francis Beaufort became famous for creating a polyalphabetic military cipher, also named after him.

Beaufort scale and its features

The scale represents the earliest classification of winds according to their strength and speed. It was developed on the basis of meteorological observations in the open sea. Initially, the classic Beaufort wind scale is a twelve-point scale. It was only in the middle of the 20th century that it was expanded to 17 levels in order to distinguish between hurricane-force winds.

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

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

It is important to note that the Beaufort scale does not allow determining 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 a detailed description of the impact 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 force (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 weathercocks 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 trees
4	5,5-7,9	The wind raises dust and small debris from the ground
5	8,0-10,7	The wind can be "felt" with your hands. The thin trunks of small trees sway.
6	10,8-13,8	Large branches sway, wires “buzz”
7	13,9-17,1	Tree trunks sway
8	17,2-20,7	Tree branches break. Going against the wind becomes very difficult
9	20,8-24,4	Wind destroys awnings and roofs of buildings
10	24,5-28,4	Significant destruction, the wind can pull trees out of the ground
11	28,5-32,6	Large destruction over large areas
12	over 32.6	Huge damage to houses and buildings. Wind destroys vegetation

Beaufort table of sea conditions

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 the open ocean

wind force (in points)	Wind speed	The effect of wind on the sea
0	0-1	The surface of the water mirror is perfectly flat and smooth
1	1-3	A small wave appears on the surface of the water, ripples
2	4-6	Short waves appear up to 30 cm in height
3	7-10	The waves are short but distinct, with foam and "lambs"
4	11-16	Elongated waves appear up to 1.5 m in height
5	17-21	The waves are long with ubiquitous "lambs"
6	22-27	Large waves are formed with splashes and foamy crests
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 spray
10	48-55	Very high waves that capsize with a strong crash. 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 severely limited
12	over 64	Hurricane. Visibility of objects is very poor. The air is saturated with spray and foam

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

IA site.

Beaufort scale

0 points - calm
A mirror-smooth sea, almost motionless. Waves practically do not run up to the shore. The water is more like a quiet backwater of a lake than a sea coast. Haze may be observed above the surface of the water. The edge of the sea merges with the sky so that the border is not visible. Wind speed 0-0.2 km/h.

1 point - quiet
Light ripples on the sea. The height of the waves reaches up to 0.1 meters. The sea can still merge with the sky. There is a light, almost imperceptible breeze.

2 points - easy
Small waves, no more than 0.3 meters high. The wind speed is 1.6-3.3 m/s, you can feel it with your face. With such a wind, the weather vane begins to move.

3 points - weak
Wind speed 3.4-5.4 m/s. Slight roughness on the water, occasionally lambs appear. The average wave height is up to 0.6 meters. A weak surf is clearly visible. The weather vane spins without frequent stops, the leaves on the trees, flags and so on sway.

4 points - moderate
Wind - 5.5 - 7.9 m / s - raises dust and small pieces of paper. The weather vane spins continuously, the thin branches of the trees bend. The sea is restless, in many places lambs are visible. Wave height up to 1.5 meters.

5 points - fresh
Almost the entire sea is covered with white lambs. Wind speed 8 - 10.7 m/s, wave height 2 meters. Branches and thin tree trunks sway.

6 points - strong
The sea in many places is covered with white ridges. The wave height reaches 4 meters, the average height is 3 meters. Wind speed 10.8 - 13.8 m/s. Thin tree trunks bend, and thick branches of trees, telephone wires buzz.

7 points - strong
The sea is covered with white foamy ridges, which are blown off the surface of the water from time to time by the wind. The wave height reaches 5.5 meters, the average height is 4.7 meters. Wind speed 13.9 - 17.1 m/s. Medium tree trunks sway, branches bend.

8 points - very strong
Strong waves, foam on each crest. The height of the waves reaches 7.5 meters, the average height is 5.5 meters. Wind speed 17.2 - 20 m/s. It is difficult to go against the wind, it is almost impossible to talk. Thin branches of trees break.

9 points - storm
High waves on the sea, reaching 10 meters; average height 7 meters. Wind speed 20.8 - 24.4 m/s. Large trees bend, medium branches break. The wind rips off poorly reinforced roof coverings.

10 points - strong storm
The sea is white. Waves crash on the shore or on the rocks with a roar. The maximum wave height is 12 meters, the average height is 9 meters. The wind, at a speed of 24.5 - 28.4 m/s, rips off roofs, significant damage to buildings.

11 points - fierce storm
High waves reach 16 meters, with an average height of 11.5 meters. Wind speed 28.5 - 32.6 m/s. Accompanied by great destruction on land.

12 points - hurricane
Wind speed 32.6 m/s. Serious damage to capital buildings. The wave height is over 16 meters.

Sea wave scale

In contrast to the generally accepted twelve-point system for estimating wind, there are several estimates of sea waves.

British, American and Russian grading systems are generally accepted.

All scales are based on a parameter that determines the average height of significant waves.

This setting is called Significance Wave Height (SWH).

In the American scale, 30% of significant waves are taken, in the British 10%, in the Russian 3%.

Wave height is measured from the crest (the top of the wave) to the trough (the base of the trough).

Below is a description of the height of the waves:

• 0 points - calm,
• 1 point - ripples (SWH< 0,1 м),
• 2 points - weak waves (SWH 0.1 - 0.5 m),
• 3 points - light waves (SWH 0.5 - 1.25 m),
• 4 points - moderate waves (SWH 1.25 - 2.5 m),
• 5 points - stormy excitement (SWH 2.5 - 4.0 m),
• 6 points - very rough sea (SWH 4.0 - 6.0 m),
• 7 points - strong excitement (SWH 6.0 - 9.0 m),
• 8 points - very strong excitement (SWH 9.0 - 14.0 m),
• 9 points - phenomenal sea (SWH > 14.0 m).

In this scale, the word "storm" is not applicable.

Since it is not determined by the strength of the storm, but by the height of the wave.

Storm is defined by Beaufort.

For the WH parameter for all scales, it is precisely a part of the waves (30%, 10%, 3%) that is taken because the magnitude of the waves is not the same.

At a certain time interval there are waves, for example, 9 meters, as well as 5, 4, etc.

Therefore, each scale has its own SWH value, where a certain percentage of the highest waves is taken.

There are no instruments for measuring wave height.

Therefore, there is no exact definition of the score.

The definition is conditional.

On the seas, as a rule, the wave height reaches 5-6 meters in height, and up to 80 meters in length.

Visibility scale

Visibility is the maximum distance at which objects are detected during the day and navigation lights at night.

Visibility depends on weather conditions.

In metrology, the influence of weather conditions on visibility is determined by a conditional scale of points.

This scale is a way of indicating the transparency of the atmosphere.

Distinguish between day and night visibility.

Below is a daily scale for determining the visibility range:

Up to 1/4 cable
About 46 meters. Very poor visibility. Thick fog or blizzard.

Up to 1 cable
About 185 meters. Bad visibility. Thick fog or sleet.

2-3 cables
370 - 550 meters. Bad visibility. Fog, wet snow.

1/2 mile
About 1 km. Haze, thick haze, snow.

1/2 - 1 mile
1 - 1.85 km. Average visibility. Snow, heavy rain

1 - 2 miles
1.85 - 3.7 km. Haze, mist, rain.

2 - 5 miles
3.7 - 9.5 km. Light haze, haze, light rain.

5 - 11 miles
9.3 - 20 km. Good visibility. Visible horizon.

11 - 27 miles
20 - 50 km. Very good visibility. The horizon is clearly visible.

27 miles
Over 50 km. Exceptional visibility. The horizon is clearly visible, the air is transparent.