What kind of clouds does hail come from? What is hail, snow pellets and freezing rain and what is the difference between them? For general development

Hail is one of the most unusual and mysterious atmospheric phenomena. The nature of its occurrence is not fully understood and remains the subject of fierce scientific debate. Does hail happen at night - the answer to this question is of interest to everyone who has never seen this rare phenomenon at night.

Brief information about the city

Hail is called atmospheric rainfall in the form of pieces of ice. The shape and size of these precipitations can vary greatly:

• Diameter from 0.5 to 15 cm;
• Weight from a few grams to half a kilogram;
• The composition can also be very different: as several layers clear ice, and alternating transparent and opaque layers;
• The form is the most diverse - up to bizarre formations in the form of "flower buds", etc.

Hailstones easily stick together, forming large particles the size of a fist. Precipitation with a diameter of more than 2 cm in diameter is already enough to cause major damage to the economy. As soon as hail of this size is expected, a storm warning is issued.

Different states may have other size thresholds: it all depends on the specific agricultural area. For example, for vineyards, even small hailstones will be enough to destroy the entire crop.

The necessary conditions

According to modern ideas about the nature of hail, for its occurrence it is necessary:

• Water drops;
• Condensation yard;
• Updrafts of air;
• Low temperature.

Similar atmospheric phenomenon occurs in 99% of cases temperate latitudes over large continental expanses. Most researchers believe that thunderstorm activity is a prerequisite.

In the tropical and equatorial zones, hail is a rather rare occurrence, despite the fact that thunderstorms occur quite often there. This happens because for the formation of ice it is also necessary that at an altitude of approximately 11 km there is enough low temperature, which does not always happen in warm places the globe. Hail occurs only in mountainous areas.

In addition, the probability of hail becomes vanishingly small as soon as the air temperature drops below -30 °C. Supercooled water drops in this case are located near and inside the snow clouds.

How does hail occur?

The mechanism of formation of this type of precipitation can be described as follows:

1. An ascending air flow containing a significant number of water droplets encounters a cloudy layer of low temperature on its way. It often happens that the strongest tornado acts as such an air flow. A significant part of the cloud must be below the freezing point (0 °C). The probability of hail formation increases a hundredfold when the air temperature at an altitude of 10 km is about -13 °.
2. Upon contact with the condensation nuclei, pieces of ice are formed. As a result of alternating up-and-down processes, the hailstones acquire a layered structure (transparent and white levels). If the wind blows in a direction where there are a lot of water droplets, a transparent layer is obtained. If it blows into the region of water vapor, the hailstones are covered with a crust of white ice.
3. In collisions with each other, ice can stick together and seriously grow in size, forming irregular shapes.
4. Hail formation can last for at least half an hour. As soon as the wind stops supporting the ever heavier storm cloud, hail will begin to fall on the earth's surface.
5. After the icicles pass the area with temperatures above 0 ° C, a slow process of their melting will begin.

Why is there no hail at night?

In order for ice particles to form in the sky of such a size that they do not have time to melt when they fall to the ground, sufficiently strong vertical air currents are needed. In turn, in order for the upward flow to be powerful enough, strong heating of the earth's surface is necessary. That is why, in the vast majority of cases, hail falls in the evening and afternoon hours.

However, nothing prevents it from falling out at night, if there is a thundercloud of sufficient size in the sky. True, at night people mostly sleep, and small hail can go completely unnoticed. That's why creates the illusion that freezing rain' happens only during the day.

With regard to statistics, in most cases hail occurs in the summer at about 15:00. The possibility of its falling out is quite high up to 22:00, after which the probability of this type of precipitation tends to zero.

Observational data from meteorologists

Among the most known cases"freezing rain" at night:

• One of the most powerful night hailstorms fell on June 26, 1998 in the Illinois village of Hazel Crest. At that time, local agriculture was seriously affected by hailstones measuring 5 cm in diameter that fell around 4 o'clock in the morning;
• On September 5, 2016, hail fell in the vicinity of Yekaterinburg, which destroyed local crops;
• In the Belarusian city of Dobrusha, on the night of August 26, 2016, ice floes the size of a fist broke the windows of cars;
• On the night of September 9, 2007, hail swept across the Stavropol Territory, which damaged 15,000 private houses;
• On the night of July 1, 1991 on Mineral water a whole icy downpour hit, which not only caused damage to local households, but even damaged 18 aircraft. The average size ice was about 2.5 cm, but there were also giant balls the size of egg.

Many people still do not know if hail happens at night. The probability of this phenomenon occurring at night is vanishingly small, but still there. Moreover, these rare cases account for many of the strongest anomalies that cause serious harm to the economy.

They should be distinguished from frost and dew, which are nothing more than condensed moisture,

settled on objects or plants. The phenomenon of fog also comes from temperature differences. For example, in autumn it comes from warmer water bodies. Steam, hitting cold air, immediately condenses. But the water suspension, due to its own gravity, cannot rise up and become a cloud, and therefore spreads near the earth itself, filling the lowlands and floodplains of the rivers. However, here we are talking about precipitation. How hail differs from grains similar to it and Learn from this article.

Transition state?

Even a primary school student will say what hail is: something between rain and snow. Droplets of water freeze and turn into ice - small and large. Falling to the ground, they make a loud noise, as if nuts or pebbles are falling. The hailstones do not immediately melt. Sometimes you can observe how they cover the ground with a carpet several tens of centimeters high. But the freezing rain, although it hurts the face, immediately turns into water. Sometimes you can hear the crystal ringing of individual "drops" on the asphalt. But more often this is accompanied by the sounds of ordinary rain. And the snow crumbles to the ground with a quiet rustle. These deposits are also different in appearance. The hailstones are large and translucent. Freezing rain is like broken glass. And grains can be likened to miniature snowballs.

How is snow formed?

To seriously understand the question of what hail is, it is simply necessary to return to the basics of natural history and remember how clouds are formed that carry rain or snow. Moisture evaporates from the earth's surface. But most often clouds form over seas-oceans, where there is more water. the air lifts the vapor up. At different heights, due to a decrease in air temperature, moisture condenses. But it does not turn into water droplets, but is converted into ice crystals, bypassing the liquid state. If the cloud is small and light, it is driven by the wind to drier areas, where it melts without giving the earth precipitation. A dense one cannot hold heavy, low-floating clouds. Ice crystals begin to fall. If the air temperature near the surface of the earth is positive, they melt, turning into raindrops. Well, if it is below zero outside the window, the crystals coalesce with each other, forming snowflakes of a wide variety of shapes and sizes.

This is a completely different type of precipitation. And it appears in completely different clouds. Maybe you remember what kind of clouds threaten us with a downpour? Dense, dark gray, sometimes even purple ... Tall, like swirling towers, they swoop in swiftly, like a tornado. Unlike a downpour, hail is rarely accompanied by lightning and thunder. But there is always a squally wind. A hailstone is born in the same way as a snowflake - from an ice crystal. But it is not formed at all in flat clouds that carry snow. Hail is generated by the very form of clouds. A tall mass rises up for several kilometers. It is clear that between the lower and top edges such a cloud has a temperature difference. Crystals closer to the ground melt, turning into drops of water (hail never falls in winter). But instead of raining down, powerful updrafts rush this moisture up, where it freezes - this time in the form of a small ice ball. If the wind movement inside the cloud is weak, small hail falls. But if the air flow is strong, then the ball that had melted was brought up again, where it is overgrown with another ice shell. Sometimes hailstones, colliding, coalesce with each other. Then their form changes. This is no longer a ball, but a complex conical or pyramidal formation. The more the drop migrates, the larger the hail. The maximum size of the ice pieces was 150 mm, and the weight was over a kilogram.

How to prevent hail

It is clear that falling to the ground at a speed of 150 kilometers per hour, serious injuries and damage can be caused by not so huge specimens. People have long thought about how to prevent the death of crops and livestock from hail. In the Middle Ages, they discovered a pattern: if you make very loud and sharp sounds, then a downpour will spill from the clouds. Therefore, when danger approached, people beat the bell or fired a cannon. From the pulsation of the air, the hailstones disintegrated, became smaller and melted before reaching the ground. Now they shoot at a dangerous cloud with a special projectile with a reagent of silver iodide or lead.

Now that we have learned what hail is, let's figure out what snow pellets are. These are small, 1-2 mm in diameter snow balls. Unlike hail, they are fragile, opaque, and white in color. In fact, these are fused and compacted snowflakes.

For general development

In modern Russian, the word "grad" has another meaning. This is the name of the reactive system. salvo fire, which replaced the outdated Katyusha. it deadly weapon was developed by A. I. Ganichev and design bureau GNPP "Splav". The basic complex is being modified from year to year, giving birth to Grad-V, P, 1A and other installations.

When hail comes, the roof and drainpipes shake with a terrible roar, hail can cause destruction. Hailstones can pierce through the wing of an aircraft, beat wheat shoots, hail kills horses, cows and other domestic animals. Per a short time hail may fall so abundant that it will cover the earth completely.

Stormy streams carry out after a strong hail of accumulation of ice up to two meters long and wide. Small hailstones are often round . They fall to the ground like little billiard balls. But it happens that the shape of the hailstones has unusual outlines: either the sun with rays, or the frozen letter “X”. Various forms are caused by the wind blowing high in the air forming a hailstone.

The largest hailstone

The largest hailstone ever seen fell in September 1970 near Coffeeville, Kansas. It was more than 40 centimeters in diameter, weighed about 800 grams, different sides ice spikes protruded. This shapeless piece of ice resembled a medieval deadly weapon.

The hailstone grows larger and larger as more and more more ice sticks to the wind-born ice "ship", rushing without a rudder and without sails on a thundercloud. If you split a hailstone, you can trace the history of its birth. Rings are visible on the fault, like rings on a stump, marking the stages of hailstone growth. One layer is transparent, the other is milky cloudy, the next is transparent again, and so on.

What causes the difference in the structure of hailstone layers?

When ice on a hailstone freezes quickly (at very low temperatures). To carry a hailstone with a diameter of about 10 centimeters through the air, ascending air jets in a thundercloud must have a speed of at least 200 kilometers, snowflakes and air bubbles are included in it. This layer looks cloudy. But if the temperature is higher, then the ice freezes more slowly, and the included snowflakes have time to melt, and the air escapes. Therefore, such a layer of ice is transparent. From the rings, you can trace which layers of the cloud the hailstone visited before falling to the ground.

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The hailstone grows, flying up and down the cloud. During this time, it becomes harder and harder. It is clear that in order for the hailstone to become substantially heavier, the wind in the cloud must be very strong. For example, in order for a hailstone to grow to 10 centimeters in diameter, the wind speed must be at least 200 kilometers per hour. These powerful currents of air carry the hailstone until its weight becomes such that the wind will no longer be able to keep it suspended. Now the hailstone is falling to the ground.

Since hailstones only grow inside clouds, the thicker the thundercloud, the greater the chance that hail will fall from it. Probability of hail from thundercloud 12 kilometers thick is equal to 50 percent. If the cloud is 2 kilometers thicker, then the chances increase to 75 percent. Well, if the thickness of the clouds is 18 kilometers, then there will be hail for sure.

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Hailstorm shade

A hailstorm may have a greenish tinge. Why? White sunlight is made up of the colors of the rainbow, or the spectrum: red, orange, green, blue, indigo and violet. Hailstones predominantly reflect green light from the composition of the spectrum sun rays, which is why hail clouds have an ominous greenish tint.

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Hail - precipitation in the form of spherical particles or pieces of ice (hailstones) with a diameter of 5 to 50 mm, sometimes more, falling out in isolation or in the form of irregular complexes. Hailstones consist only of transparent ice or a series of its layers at least 1 mm thick, alternating with translucent layers. Hail usually occurs during heavy thunderstorms.

City formation.

What is the mechanism of hail formation? Hypotheses about this were built by Descartes in the first half of the 17th century. However, the scientific theory of hail processes and methods of influencing them was created by physicists together with meteorologists only in the middle of the last century.

Warm air rising from the earth's surface on a hot summer day cools with height, and the moisture contained in it condenses, forming a cloud. Bypassing the zero isotherm at a certain height, the smallest drops of water become supercooled. Supercooled drops in the clouds are found even at a temperature of minus 40 °.

Hail is formed in a powerful cumulus cloud with strong ascending air currents. Their speed usually exceeds 15 m / s (average speed passenger train). Large supercooled (up to -10…-20°C) water drops are supported on these streams. The higher, the lower the speed of air flows, the more difficult it is for them to hold drops. But these drops are very unstable. Raised from the earth's surface, the smallest particles of sand, salt, combustion products, and even bacteria, when colliding with supercooled drops, upset the delicate balance. Supercooled droplets that come into contact with solid condensation nuclei turn into an ice hailstone embryo.

Small hailstones exist in the upper half of almost every cumulonimbus cloud, but most often such hailstones melt as they fall towards the earth's surface. So, if the speed of ascending flows in a cumulonimbus cloud reaches 40 km / h, then they are unable to keep the emerging hailstones, therefore, passing through the warm layer of air between the zero isotherm (on average, the height is from 2.4 to 3.6 km) and the earth's surface, they fall out of the cloud in the form small "soft" hail, or even in the form of rain. Otherwise, ascending air currents raise small hailstones to layers of air with a temperature of -10 to -40 degrees (height between 3 and 9 km), the diameter of the hailstones begins to grow, sometimes reaching a diameter of several centimeters.

At an altitude of 8-10 km, where the temperature reaches -35...-40°C, the drops freeze, ice particles form - hailstone embryos. Hitting each other, colliding with supercooled drops that have not yet had time to freeze, they freeze them to themselves, get fatter, heavier and descend into lower clouds, where there are even more supercooled drops. To "gain" 1 cm in diameter, each hailstone must experience approximately 100 million collisions with cloud droplets.

It is worth noting that in exceptional cases, the speed of updrafts and downdrafts in the cloud can reach 300 km/h! And the higher the speed of updrafts in a cumulonimbus cloud, the larger the hail. A golf ball-sized hailstone would require over 10 billion supercooled water droplets to form, and the hailstone itself would have to stay in the cloud for at least 5 to 10 minutes to reach that level. large size. It is worth noting that the formation of one drop of rain requires about a million of these small supercooled drops. Hailstones larger than 5 cm in diameter are found in supercellular cumulonimbus clouds, in which very powerful updrafts are observed. It is super-cell thunderstorms that generate tornadoes, heavy downpours and intense squalls.

When a hailstone reaches such a mass that the updraft is unable to hold it, it rushes to the surface of the earth, and we observe a large hail fall. When observing hail, carefully cutting the hailstone, you will notice that frosted layers of ice will alternate in the form of rings with layers of transparent ice. Thus, by the number of such rings, one can determine how many times the hailstone was raised by ascending air currents in the cloud.

The fall speed of hailstones with diameters of 4 cm can reach 100, and larger hailstones rush to the ground at a speed of 160 km/h. It is not difficult to guess what kind of destruction hail damage can cause. But not every large hailstone will reach the ground: falling in a cloud, the hailstones collide with each other, while collapsing and turning into smaller hailstones that melt in the warm air. On average, 40 - 70% of the formed hailstones do not reach the surface of the earth, melting in the warm air. Hail usually falls during heavy thunderstorms in warm time year, when the temperature at the surface of the earth is not lower than 20 ° C.

The fallout of hail occurs like an avalanche. Sometimes, in a matter of minutes, hail covers the earth with ice balls with a layer of 5-7 cm. In the Kislovodsk region in 1965, hail fell, covering the earth with a layer of 75 cm! Most often, hail falls in a narrow (no more than 10 kilometers), but long (sometimes hundreds of kilometers) strip. The area of ​​the hail zone can vary from one hectare to several tens of kilometers. AT last case hail zones correspond to the squall line.

Hail is a disaster less terrible than a hurricane or an earthquake, but it, both in the old days and now, often causes huge losses. Hail breaks vines and branches of fruit trees, knocks down fruits from them, destroys grain crops, breaks sunflower and corn stalks, knocks out tobacco and melon plantations. Often, hailstones kill poultry, small, and sometimes cattle.

In 1593, "... on Sunday, the eleventh day of the month of June, on the day of the Holy Trinity, at seven o'clock in the evening there was such a strong thunderstorm with thunder, lightning, rain and hail, which until then people had not heard of. Some hailstones ... weighed from 18 to 20 pounds each. As a result of this, great damage was done to crops and many churches, castles, houses and other structures were destroyed. The vineyards did not bear fruit after this for 5-6 years; the forest was uprooted and felled to the ground. Such horror seized the people that there was no a man, however brave he may be, who would not prepare for death. Many were killed and wounded, others lost their minds. Many livestock, both domestic and wild, perished." This is an excerpt from a historical record kept in one of the southern departments of France. Perhaps there is some exaggeration here, it is known that "fear has big eyes." Doubtful so big weight hailstones, but it must be taken into account that in those days the pound as a unit of weight had several meanings. However, it is clear that this was a terrible natural disaster, one of the most catastrophic hailstorms that hit France.

In the eastern part of the state of Colorado (USA), about six hailstorms occur annually, each of them brings huge losses. In our country, hailstorms most often occur in the North Caucasus, in Georgia, Armenia, in mountainous regions Central Asia. Here is one of the laconic messages from the Nalchik weather station: “From June 9 to June 10, 1939 ... hail fell the size of a chicken egg, accompanied by heavy rain. As a result, more than 60 thousand hectares of wheat and about 4 thousand hectares of other crops died; about 2 were killed thousand sheep.

It has long been noted that there are areas that suffer from hail year after year. Some farmers are even convinced that in some fields hail will certainly knock out crops, while the neighboring plot will not suffer. For the inhabitants of England, hail is a rarity, and French winegrowers living on the other side of the English Channel curse it several times a year. In the tropics, hail almost never falls, although thunderstorms often flare up there. So, in Brazzaville there are up to 60 thunderstorms a year, but in the entire history of the city, hail has never been registered there.

When talking about the fallen hail, first of all note the size of the hailstones. They are usually all different in size. The biggest draw attention. And now we learn about absolutely fantastic hailstones. In India and China, cases of falling from the sky of ice blocks weighing 2-3 kilograms are known. They even talk about such a sad incident: in 1961, in North India, a heavy hailstone killed an elephant. In our temperate latitudes, hailstones weighing about a kilogram were observed. There is a known case when in Voronezh hail broke the tiles on the roof of the house, broke through the metal roof of the bus. These are indirect signs by which they also judge the size of hailstones. Sometimes it is possible to take photographs with a scale - an object of well-known sizes (a coin, a watch, etc.) is placed next to the hailstone. Matchbox, and even better - a ruler.)

One of the hailstones, photographed in the USA, had a diameter of 12 cm, 40 cm in circumference, and weighed 700 g. Elongated hailstones about the size of a palm (15 X 9 cm) were registered in France. The weight of individual hailstones reached 1200 g! And there were 5-8 such hailstones per square meter. So the ancient chroniclers, perhaps, did not greatly exaggerate what they saw.

But these are all exceptional cases. Usually even hailstones with a diameter of 25 mm or more are rare. Not every old-timer can remember hail the size of a chicken egg ...

Hail Fighting:

At all times, hail has caused the greatest damage to agriculture. Therefore, since very ancient times, people began to look for means to combat this natural disaster. Herodotus tells how the Thracians shot arrows into hail clouds. Of course, it was a gesture of desperation. And in later centuries they shot at the clouds from guns, from cannons. But the shooters had no idea what, in fact, the projectile should do with the cloud. And even in our century, attempts to use to combat the hail cloud state-of-the-art technology- aviation and missiles - ended to no avail. It is known that in Italy in the 1955 season, about one hundred thousand rockets were fired at the clouds carrying hail.

It is estimated that to create a summer cumulus cloud nature "expends" millions of kilowatts. Involuntarily you will think: is there a force capable of destroying it? Fortunately, as meteorologists have found out, it is not required to destroy clouds. Atmospheric processes are sometimes in such an unstable state that with a relatively small intervention it is possible to push their course in the desired direction.

This is exactly what meteorologists achieve when they storm clouds. The sizes of hail clouds are huge, sometimes several thousand square kilometers, it is not difficult to hit such a target with a projectile, but the result from this is negligible - nothing more than a pellet for an elephant. I had to find vulnerable spot- "Achilles' heel" of a giant cloud. Calculations and experiments of meteorologists and physicists have shown that hail originates in a relatively small (20-30 cubic kilometers), the so-called large-drop zone of the cloud, and it is precisely on it that "pressure" must be exerted. But how to do that?

Most effective method- artificially create a large number of hail germs. Each "newborn" will intercept droplets of supercooled water, and its reserves in the cloud are limited. Each of the embryos prevents the growth of the other, so the hailstones are small. Such a hail, falling on the ground, will not cause serious damage, and it is very possible that instead of hail there will be a downpour. This is already a victory!

Artificial hail nuclei are created when dry carbon dioxide or silver iodide, lead is introduced into the supercooled part of the cloud. One gram creates 1012 (trillion) ice crystals.

The difficulty is to determine the hail zone in the cloud and spray reagents there in time. In general, the whole fight against hail resembles air defense.

Radars detect a hail cloud almost 40 km before the protected areas. Hail clouds develop very quickly. The whole process of hail formation takes 30-40 minutes, so it is necessary to act on the cloud no later than 15-20 minutes after the start of its rapid development. They specify the coordinates of the large-drop zone and use anti-aircraft guns equipped with special projectiles or missiles.

A large anti-hail rocket "Oblako" carries approximately 3 kg of a special reagent. In the head and tail of the rocket there are remote mechanisms that, at the required height and at a certain section of the rocket's flight path, ignite the pyrotechnic composition and eject the parachute. The rocket descends by parachute, emitting smoke containing tiny particles of lead iodide. The flight of the rocket passes through the supercooled parts of the cloud, where myriads of ice crystals form on the aerosol particles. It is they who become artificial embryos of hailstones.

Having done its job, the rocket slowly descends to the ground and usually becomes the prey of the children. It is completely safe, which allows you to work in densely populated areas. The range of "Clouds" is 10 km.

Grad - a natural phenomenon, known to almost every inhabitant of the planet on personal experience, from movies or from the pages printed publications. At the same time, few people think about what such precipitation really is, how they form, whether they are dangerous for humans, animals, crops, etc. Not knowing what hail is, you can be seriously scared when you encounter such a phenomenon for the first time. So, for example, the inhabitants of the Middle Ages were so afraid of ice falling from the sky that even with indirect signs of their appearance, they began to sound the alarm, ringing bells and firing cannons!

Even now, in some countries, special crop covers are used to save the crop from heavy rainfall. Modern roofs are designed with increased resistance to hailstone impacts, and caring hosts cars are sure to try to protect their vehicles from falling under the “shelling”.

Is hail dangerous for nature and humans?

In fact, such precautions are far from unreasonable, because a large hail can really cause serious damage to property and the person himself. Even small pieces of ice falling from a great height acquire significant weight, and their impact on any surface is quite noticeable. Every year, such precipitation destroys up to 1% of all vegetation on the planet, and also causes serious damage to the economy. different countries. So the total amount of losses from hail is more than 1 billion dollars annually.

You should also remember how dangerous hail is for living beings. In some regions, the weight of falling ice floes is sufficient to injure or even kill an animal or person. Cases have been recorded when hailstones pierced the roofs of cars and buses and even the roofs of houses.

In order to determine the degree of danger of ice and respond in time to a natural disaster, one should study hail as a natural phenomenon in more detail, as well as take basic precautions.

Grad: what is it?

Hail is a type of rainfall that occurs in rain clouds. Ice floes can form in the form of round balls or have jagged edges. Most often these are white peas, dense and opaque. The hail clouds themselves are characterized by a dark gray or ashy hue with ragged white ends. The percentage probability of solid precipitation depends on the size of the cloud. With a thickness of 12 km, it is approximately 50%, but when it reaches 18 km, hail will be a must.

The size of ice floes is unpredictable - some may look like small snowball while others reach several centimeters in width. The largest hail was seen in Kansas, when “peas” up to 14 cm in diameter and weighing up to 1 kg fell from the sky!

May be accompanied by hail precipitation in the form of rain, in rare cases - snow. There are also loud peals of thunder and flashes of lightning. In prone regions, severe hail may occur along with a tornado or tornado.

When and how hail occurs

Most often, hail forms in hot weather during the daytime, but in theory it can appear up to -25 degrees. It can be seen during rain or just before other precipitation. After a downpour or snowfall, hail occurs extremely rarely, and such cases are the exception rather than the rule. The duration of such precipitation is short - usually everything ends in 5-15 minutes, after which you can observe good weather and even bright sunshine. However, the layer of ice that has fallen out in this short period of time can reach several centimeters in thickness.

Cumulus clouds, in which hail is formed, consist of several separate clouds located at different heights. So the top ones are more than five kilometers above the ground, while others “hang” quite low, and they can be seen with the naked eye. Sometimes these clouds resemble funnels.

The danger of hail is that not only water gets inside the ice, but also small particles of sand, debris, salt, various bacteria and microorganisms, which are light enough to rise into the cloud. They are held together with the help of frozen steam and turn into large balls that can reach record sizes. Such hailstones sometimes rise several times into the atmosphere and fall back into the cloud, collecting more and more "components".

To understand how hail is formed, just look at one of the fallen hailstones in the section. In structure, it resembles an onion, in which transparent ice alternates with translucent layers. Secondly, there is various "garbage". Out of curiosity, you can count the number of such rings - that is how many times the ice rose and fell, migrating between the upper layers of the atmosphere and the rain cloud.

Causes of hail

In hot weather, hot air rises, carrying with it particles of moisture that evaporate from water bodies. In the process of lifting, they gradually cool down, and when they reach a certain height, they turn into condensate. Clouds are obtained from it, which soon rain or even a real downpour. So if there is such a simple and understandable water cycle in nature, then why does hail happen?

Hail happens because on particularly hot days, hot air flows rise to record heights, where temperatures drop well below freezing. Supercooled droplets that crossed the threshold of 5 km turn into ice, which then fall out as precipitation. At the same time, even for the formation of a small pea, more than a million microscopic particles of moisture are needed, and the speed of air flows must exceed 10 m/s. It is they who keep the hailstone inside the cloud for a long time.

As soon as the air masses are not able to support the weight of the formed ice, hailstones break down from a height. However, not all of them reach the ground. Small pieces of ice will have time to melt along the way, and fall out in the form of rain. Since quite a few factors are required to coincide, the natural phenomenon of hail is quite rare and only in certain regions.

Precipitation geography or at what latitudes hail can fall

Tropical countries, as well as inhabitants of the polar latitudes, practically do not suffer from precipitation in the form of hail. In these regions, a similar natural phenomenon can only be found in the mountains or on high plateaus. Also, hail is rarely observed over the sea or other bodies of water, since in such places there are practically no ascending air currents. However, the chance of precipitation increases as you get closer to the coast.

Usually hail falls in temperate latitudes, while here it “chooses” lowlands, and not mountains, as is the case with tropical countries. There are even certain lowlands in such regions, which are used to study this natural phenomenon, since it occurs there with enviable frequency.

If, nevertheless, precipitation finds an outlet in rocky terrain in temperate latitudes, then they acquire the scale of a natural disaster. Ice floes are formed especially large and fly from a great height (more than 150 km). The fact is that in especially hot weather, the relief warms up unevenly, which leads to the emergence of very powerful updrafts. So drops of moisture rise along with air masses 8-10 km, where they turn into hailstones of a record size.

They know firsthand what a city is, the inhabitants of North India. During the summer monsoons, ice up to 3 cm in diameter often falls from the sky, but larger-scale precipitation also occurs, which cause serious inconvenience to the local natives.

At the end of the 19th century, such a strong hail passed through India that more than 200 people died from its blows. Ice precipitation is also causing serious damage to the American economy. Heavy hail falls almost throughout the country, which destroys crops, breaks the road surface and even destroys some buildings.

How to escape from a large hail: precautions

It is important to remember, having met hail on the road, that this is a dangerous and unpredictable natural phenomenon that can pose a serious threat to life and health. Even small peas, falling on the skin, can leave bruises and abrasions, and if a large ice floe hits the head, a person may well lose consciousness or get seriously injured.

At the beginning, the ice may be a little smaller, and during this time, you should find a suitable shelter. So, if you are in a vehicle, do not go outside. Try to find a parking garage, or stop under a bridge. If this is not possible, park the car at the curb and move away from the windows. With sufficient dimensions of your vehicle- lie down on the floor. For safety reasons, cover your head and exposed skin with a jacket or blanket, or at least cover your eyes with your hands as a last resort.

If during rainfall you find yourself in an open area, urgently find a reliable shelter. At the same time, it is categorically not recommended to use trees for this purpose. Not only can they be struck by lightning, which is a constant companion of hail, but ice balls can also break branches. Injuries received from chips and branches are no better than bruises from hailstones. In the absence of any canopy, just cover your head with improvised material - a board, plastic lid, a piece of metal. In extreme cases, a tight denim or leather jacket is suitable. You can fold it in several layers.

It is much easier to hide from hail indoors, but with a large diameter of ice, precautions should still be taken. Turn off all electrical appliances by pulling the plugs out of sockets, move away from windows or glass doors.