The largest hail weighed according to the recollections of contemporaries. The largest city
Thunderstorms in Moscow and the Moscow region are sometimes accompanied by hail, mostly small, no larger than a pea. Muscovites also witnessed hail the size of cherries, walnuts and even larger.
More recently, on May 16, 1959, a thunderstorm in Moscow was accompanied by heavy rain and very large hail. Water flooded the asphalt of Trubnaya and Tishinskaya squares, there was a sea of water at the Zoo, at the Dynamo stadium and in other places. Traffic was temporarily suspended. Hailstones the size of walnuts fell with great noise, raising meter-long columns of water in the puddles. In the Dzerzhinsky and Kuibyshevsky regions, the size of individual hailstones reached 4-5 cm. In those places where hail fell before the rain, one could see “explosions” of hailstones when they hit the asphalt. Some hailstones looked like rolled balls of snow, which, falling to the ground, were flattened.
Hail forms in powerful thunderclouds with a low-lying ash cloud base. Strong updrafts carry raindrops into the low temperature zone of the cloud, where they become supercooled and, rising even higher, quickly freeze. The further enlargement of hailstones can be judged by their structure. A large hailstone, cut in half, has a layered structure, like an onion. This indicates a gradual build-up of layers of ice during the relatively long journey of the hailstone in the cloud. The hailstone is either picked up by the rising flow, then falls down, then rises again and falls again. Ice is constantly frozen on it until it becomes so heavy that it flies down like a stone. Updrafts of hurricane force can support hailstones weighing hundreds of grams. On June 29, 1904, hail fell in Moscow the size of an adult man's fist, weighing more than 400 g. The hail killed small livestock and seriously injured large ones. The force of the hailstones was so great that the glass broken in the greenhouses had smooth holes, without radial cracks. The hailstones were half buried in the soft ground. Such a large city is an exceptional phenomenon.
Hail causes great harm to agriculture, knocking out crops and damaging orchards. Hail sometimes falls. without thunderstorms, but, as a rule, where there are more thunderstorms, there is more hail.
Science is looking for ways to combat hail, and these days this issue has been fundamentally resolved. Scientists are conducting successful experiments on dispersing powerful cumulus clouds by throwing solid carbon dioxide (dry ice) from an airplane. We know that powerful cumulus clouds in the next stage of development turn into thunderstorms. By dispersing them, we can prevent the occurrence of thunderstorms and, consequently, hail.
Hail is one of the most unpleasant natural phenomena. Of course, in terms of destructive power it cannot be compared with a tsunami or earthquake, but hail can also cause enormous damage.
Every year, hail damages crops, damages buildings, cars, property, and even kills animals.
People have always sought to explain the nature of hail, predict its fall, and reduce the damage caused. Despite the fact that modern meteorology has explained how hail appears and has learned to predict its occurrence in a particular region with great accuracy, hail still plagues people.
Hail: 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. Hail clouds themselves are characterized by a dark gray or ashy hue with jagged 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, there will definitely be hail.
The size of the ice floes is unpredictable - some can look like fine snow, 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!
Hail may be accompanied by precipitation in the form of rain and, in rare cases, snow. There are also loud rumbles of thunder and flashes of lightning. In susceptible regions, large hail may occur in conjunction with a tornado or waterspout.
When and how does hail occur?
Most often, hail forms in hot weather during the daytime, but in theory it can occur down to -25 degrees. It can be noticed during rain or immediately before other precipitation falls. After a rainstorm or snowfall, hail occurs extremely rarely, and such cases are the exception rather than the rule. The duration of such precipitation is short - it usually ends in 5-15 minutes, after which you can observe good weather and even bright sunshine. However, the layer of ice that falls in this short period of time can reach several centimeters in thickness.
Cumulus clouds, in which hail forms, consist of several individual clouds located at different heights. So the top ones are more than five kilometers above the ground, while others “hang” quite low and can be seen with the naked eye. Sometimes such 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 that are light enough to rise into the cloud. They are held together by frozen steam and turn into large balls that can reach record sizes. Such hailstones sometimes rise into the atmosphere several times and fall back into the cloud, collecting more and more “components.”
To understand how hail forms, just look at a cross-section of one of the fallen hailstones. Its structure 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 - this is how many times the piece of 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 bodies of water. During the rise, they gradually cool, and when they reach a certain height, they turn into condensate. From it clouds are formed, which soon become 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 occurs because on particularly hot days, currents of hot air rise to record heights, where temperatures drop well below zero. Supercooled droplets that cross a threshold of 5 km turn into ice, which then falls in the form of precipitation. Moreover, even to form a small pea, more than a million microscopic particles of moisture are needed, and the speed of air flows must exceed 10 m/s. They are the ones who hold the hailstone inside the cloud for a long time.
As soon as the air masses are not able to withstand the weight of the formed ice, hailstones fall down from a height. However, not all of them will reach the ground. Small pieces of ice will melt along the road and fall as rain. Since quite a few factors need to coincide, the natural phenomenon of hail is quite rare and only in certain regions.
Back in the Middle Ages, people noticed that after a loud sound, rain and hail either did not fall at all, or hailstones fell to the ground much smaller than usual. Not knowing why and how hail forms, in order to avoid disaster, to save crops, at the slightest suspicion of the possibility of huge ice balls, they rang bells, and if possible, even fired cannons.
Hail is a type of rainfall that forms in large cumulonimbus clouds that are ashen or dark gray in color with white ragged tops. After this, it falls to the ground in the form of small spherical or irregularly shaped particles of opaque ice.
The size of such ice floes may well vary from a few millimeters to several centimeters (for example, the size of the largest peas that were recorded by scientists was 130 mm, and their weight turned out to be about 1 kg).
This precipitation is quite dangerous: studies have shown that every year about 1% of the vegetation on Earth is killed by hail, and the damage they cause to the economies of different countries of the world is about $1 billion. They also cause trouble for residents of the region where the hail has occurred: large hailstones are quite capable of destroying not only crops, but also breaking through the roof of a car, the roof of a house, and in some cases, even killing a person.
How is it formed?
Precipitation of this type occurs mainly in hot weather, during the day, and is accompanied by lightning, thunder, downpours, and is also closely associated with tornadoes and tornadoes. This phenomenon can be observed either before or during rain, but almost never after. Despite the fact that such weather lasts relatively short time (on average about 5-10 minutes), the layer of precipitation that falls on the ground can sometimes be several centimeters.
Each cloud that carries summer hail consists of several clouds: the lower one is located low above the surface of the earth (and can sometimes stretch out in the form of a funnel), the upper one is at an altitude significantly exceeding five kilometers.
When the weather is hot outside, the air heats up extremely strongly and, together with the water vapor contained in it, rises, gradually cooling. At a great height, the steam condenses and forms a cloud that contains drops of water, which may well fall onto the earth's surface in the form of rain.
Due to the incredible heat, the updraft can be so strong that it can carry steam to a height of 2.4 km, where temperatures are much below zero, as a result of which water droplets become supercooled, and if they rise higher (at an altitude of 5 km) they begin to form hailstones (At the same time, it usually takes about a million tiny supercooled drops to form one such piece of ice).
For hail to form, it is necessary that the air flow speed exceeds 10 m/s, and the air temperature is not lower than -20°, -25°C.
Together with water droplets, tiny particles of sand, salt, bacteria, etc. rise into the air, onto which frozen steam adheres, and causes hail to form. Once formed, the ice ball is quite capable of rising several times on the updraft to the upper layers of the atmosphere and falling back into the cloud.
If an ice pellet is cut into pieces, it can be seen to consist of layers of transparent ice alternating with translucent layers, thus resembling an onion. To determine exactly how many times it rose and fell in the middle of a cumulonimbus cloud, you just need to count the number of rings;
The longer such a hailstone flies through the air, the larger it becomes, collecting not only droplets of water, but in some cases even snowflakes along the way. Thus, a hailstone with a diameter of about 10 cm and a weight of almost half a kilogram may well form.
The higher the speed of the air currents, the longer the ice ball flies through the cloud and the larger it becomes.
A hailstone flies across a cloud as long as the air currents are able to hold it. After the piece of ice gains a certain weight, it begins to fall. For example, if the speed of the upward flow in a cloud is about 40 km/h, it is not able to hold hailstones for a long time - and they fall down quite quickly.
The answer to the question why ice balls formed in a small cumulonimbus cloud do not always reach the earth's surface is simple: if they fall from a relatively small height, they manage to melt, resulting in showers falling on the ground. The thicker the cloud, the greater the likelihood of freezing precipitation. Therefore, if the cloud thickness is:
- 12 km – the probability of occurrence of this type of precipitation is 50%;
- 14 km – chances of hail – 75%;
- 18 km – heavy hail will definitely fall.
Where is ice precipitation most likely to be seen?
This kind of weather can't be seen everywhere. For example, in tropical countries and polar latitudes this is a rather rare phenomenon, and icy precipitation occurs mainly either in the mountains or on high plateaus. There are lowlands here where hail can be observed quite often. For example, in Senegal it not only often falls, but often the layer of icy precipitation is several centimeters deep.
The regions of Northern India suffer quite heavily from this natural phenomenon (especially during the summer monsoons), where, according to statistics, every fourth hailstone is more than 2.5 cm.
The largest hail was recorded here by scientists at the end of the 19th century: the ice peas were so huge that 250 people were beaten to death.
Most often, hail falls in temperate latitudes - why this happens largely depends on the sea. At the same time, if it occurs much less frequently over expanses of water (upward air currents occur more often over the earth’s surface than over the sea), then hail and rain fall close to the shore much more often than far from it.
Unlike tropical latitudes, in temperate latitudes there is much more ice precipitation in lowlands than in mountainous areas, and they can be seen more often on more uneven ground surfaces.
If hail does fall in mountainous or foothill areas, it turns out to be dangerous, and the hailstones themselves are extremely large in size. Why is this so? This happens primarily because in hot weather the relief here warms up unevenly, very powerful upward currents arise, raising steam to a height of up to 10 km (it is there that the air temperature can reach -40 degrees and is the cause of the largest hail flying to the ground from speed of 160 km/h and bringing with it trouble).
What to do if you find yourself under heavy precipitation
If you are in a car when the weather turns bad and hail falls, then you need to stop the car near the side of the road, but without driving off the road, since the ground may simply wash away and you will not get out. If possible, it is advisable to hide it under a bridge, put it in a garage or covered parking lot.
If it is not possible to protect your car from precipitation during such weather, you need to move away from the windows (or better yet, turn your back to them) and cover your eyes with your hands or clothes. If the car is large enough and its dimensions allow, you can even lie on the floor.
It’s absolutely forbidden to leave the car when it’s raining and hailing! Moreover, you won’t have to wait long, since this phenomenon rarely lasts longer than 15 minutes. If you are indoors during a rainstorm, you need to move away from the windows and turn off electrical appliances, since this phenomenon is usually accompanied by a thunderstorm with lightning.
If such weather finds you outside, you need to find shelter, but if there is none, you definitely need to protect your head from hailstones falling at great speed. It is advisable not to hide under trees during such a downpour, since large hailstones can break branches, which can seriously injure you if they fall.
Hail is a type of precipitation. It consists of ice particles of various shapes (both round and irregular), the size of which usually ranges from a couple of millimeters to several centimeters. Hailstones consist of several layers of transparent and translucent ice, which alternate with each other. This is not to say that this phenomenon is common. So, according to statistics, hail occurs in approximately one out of 800 thunderstorms.
The layer of precipitation usually amounts to no more than a few centimeters, but this directly depends on the duration of the precipitation - it ranges from a couple of minutes to one hour. It should be noted that hail usually falls in the warm season - hailstones are formed in a supercooled cloud as a result of the freezing of some drops. But large hailstones appear only in cases where there are strong air currents in the cloud, which can keep them from falling to the ground.
This natural phenomenon, although beautiful, can cause a lot of problems. First of all, we are talking about agriculture - hailstones simply destroy crops. And if they are large, then people, cars, houses suffer...
It is worth noting that sometimes a foreign object can be found in hailstones. So, in one of the cities of the USA, during precipitation, a huge ice floe fell to the ground, inside of which there was... A small turtle!
It is difficult to say which city should be considered the largest in the world. Thus, according to unofficial information, in the early 80s of the last century, hailstones fell in the Chinese province of Guangdong, the weight of which reached as much as 7 kilograms! They say that several people died then, and several tens of thousands of houses were destroyed, both partially and completely.
In 1929, hail fell in India, the diameter of which reached 13 centimeters and the weight of more than one kg. It became a real disaster for the people living in that area, because it not only mutilated the houses of local residents, but also destroyed all the crops. It lasted about 15 minutes and ended as quickly as it began.
Large hail was also noticed in Nebraska in 2003 (the largest hailstone weighed more than 1.5 kg), in Bangladesh (about 1 kg), and Kansas in 1970 (500-700 g).
Hail in different countries
According to weather observations, the largest hail that ever fell on earth was in April 1981 in Guangdong Province, China. Hailstones weighing 7 kilograms were found there. Hail is usually small in size, with a diameter of about 4.5 centimeters. As a result of the severe natural disaster, 5 people were killed and about 10,500 buildings were destroyed.
In addition, here is some more information about large hail found in various sources:
The hailstones that fell in Huderabad (India) in 1939 weighed about a kilogram. The weight of individual hailstones reached 3.4 kilograms!
Large hail also occurred in Coffeeville, Kansas on September 3, 1970. The diameter of the hailstones was more than 14.2 centimeters, and the circumference was about 44.45 centimeters. The hailstones weighed up to 755 grams.
During the tornado in Kansas, USA on May 30, 1879, hailstones up to 38 cm in diameter were observed. After their fall, holes formed in the ground, measuring 17 by 20 centimeters.
Facts about the city
Although this is not the limit. Based on the effects of hail, the destruction left by it, the world's largest hail fell in 1902 in China.
Often, hail falls to the ground with something inside it. This happens because inside the cloud that generated the hail, the ascending and descending currents are very strong. The object inside does not fall back to the ground, but moves up and down inside the cloud, comes into contact with supercooled drops and becomes a center of condensation, turning into large hail. For example, in Bovina (USA) in 1894, a hailstone fell, inside which a turtle 20 centimeters long was trapped.
Elena Pokidaeva, Samogo.Net