Storm, hurricane, tornado: concept, causes. Damaging factors and medical consequences

Tornado (synonyms - tornado, thrombus, meso-hurricane) - a strong whirlwind formed in hot weather under a well-developed cumulonimbus cloud and spreading towards the surface of the earth or body of water in the form of a giant dark rotating column or funnel.

The vortex has a vertical (or slightly inclined to the horizon) axis of rotation, the height of the vortex is hundreds of meters (in some cases 1-2 km), the diameter is 10-30 m, the lifetime is from several minutes to an hour or more.

The tornado passes through a narrow strip, so there may not be a significant increase in wind directly at the weather station, but in fact inside the tornado the wind speed reaches 20-30 m/s or more. A tornado is most often accompanied by heavy rain and thunderstorms, sometimes hail.

In the center of the tornado there is very low pressure, as a result of which it sucks into itself everything that it encounters on the way, and can lift water, soil, individual objects, buildings, sometimes carrying them over considerable distances.

Possibilities and methods of forecasting

A tornado is a phenomenon that is difficult to predict. The tornado monitoring system is based on a system of visual observations by a network of stations and posts, which practically allows only the azimuth of the tornado’s movement to be determined.

By technical means Weather radars are sometimes used to detect tornadoes. However, conventional radar is not able to detect the presence of a tornado because the size of the tornado is too small. Cases of tornadoes being detected by conventional radars were noted only very close range. Radar can be of great help when tracking a tornado.

When the radio echo of a cloud associated with a tornado can be identified on the radar screen, it becomes possible to warn about the approach of a tornado one to two hours in advance.

IN operational work A number of meteorological services use Doppler radars.

Protection of the population during hurricanes, storms, tornadoes

In terms of the speed of spread of the danger, hurricanes, storms and tornadoes can be classified as emergency events with a moderate speed of spread, which allows for a wide range of preventive measures to be carried out both in the period preceding the immediate threat of occurrence and after their occurrence - until the moment of direct impact.

These time-based measures are divided into two groups: advance (preventive) measures and work; operational protective measures carried out after the announcement of an unfavorable forecast, immediately before a given hurricane (storm, tornado).

Advance (preventive) measures and work are carried out in order to prevent significant damage long before the onset of the impact of a hurricane, storm and tornado and can cover a long period of time.

Advance measures include: restrictions on land use in areas prone to hurricanes, storms and tornadoes; restrictions on the location of hazardous production facilities; dismantling of some outdated or fragile buildings and structures; strengthening industrial, residential and other buildings and structures; carrying out engineering and technical measures to reduce the risk of hazardous industries in strong wind, incl. increasing the physical resistance of storage facilities and equipment containing flammable and other hazardous substances; creation of material and technical reserves; training of the population and rescue personnel.

Protective measures carried out after receiving a storm warning include: forecasting the path and time of approach to various areas of a hurricane (storm, tornado), as well as its consequences; promptly increasing the size of the material and technical reserve necessary to eliminate the consequences of a hurricane (storm, tornado); partial evacuation of the population; preparation of shelters, basements and other buried premises to protect the population; moving unique and especially valuable property into durable or recessed premises; preparation for restoration work and life support measures for the population.

Tornadoes are not frequent in Russia. The most famous are the Moscow tornadoes of 1904. Then, on June 29, several craters descended from a thundercloud over the outskirts of Moscow, destroying a large number of buildings, both urban and rural. Tornadoes were accompanied by thunderstorm phenomena - darkness, thunder and lightning.

The material was prepared based on information from open sources

Tornado (in America it is called a tornado) represents a strong small-scale atmospheric vortex(diameter up to 1000 m), in which air rotates at speeds up to 100 m/s, with great destructive force. It has the appearance of a pillar (sometimes with a curved axis of rotation) with a diameter of tens to hundreds of meters with funnel-shaped extensions at the top and bottom. The air in a tornado rotates counterclockwise and at the same time rises in a spiral, drawing dust, water and various items. Tornadoes do not exist for long, from several minutes to several hours, during which time they travel from hundreds of meters to tens of kilometers.

The classification of tornadoes according to their origin, structure, duration of action and space coverage is shown in Diagram 14.

This is how an eyewitness describes the tornado: “A dark gray cloud with torn, tousled edges quickly grew on the horizon. The first gusts of cold wind came. The lead edge of the cloud extinguished the last rays of the sun and immediately, as if waiting for this, reached out to the ground. The black wriggling appendage resembled a huge trunk. He rushed over earth's surface together with the cloud, now shortening, now lengthening, as if trying to see what was happening below. And towards him a funnel of a whirlwind was already rising from below, in its embrace torn off tree branches, road dust, and mown grass were spinning in a frenzied dance. Moments - and the two parts of the vortex merge into one black pillar, connecting heaven and earth. Expanding at the top and bottom, it moves along the ground with a dull roar, resembling a huge vacuum cleaner: everything that comes along the way is sucked into its belly.”

Tornadoes occur in all areas globe. In Russia, they most often occur in the Volga region and Siberia, in the Urals and the Black Sea coast.

In Russia, tornadoes have been observed since ancient times. One of the most powerful tornadoes passed over Sevastopol on September 8, 1820. It destroyed the artillery magazine, devastated local market, moved the boat 60 m, passed through the bay, lifting stones weighing up to 600 kg from the water. The tornado passed through the city in 8 minutes, but this was enough to cause severe destruction to the city.

The tornado also visited Moscow. A huge cloud approached Moscow on June 29, 1904. In the center of it, Muscovites saw something similar to a huge rope. The tornado scattered people and carts, destroyed trees, and carried cows through the air. Frequent and strong lightning killed two people and caused fires in the city. The tornado was accompanied by extraordinary rain and hail. Individual hailstones reached a mass of 600 g. Several people were killed by the hail. The tornado traveled about 40 km that day, destroying several villages near Moscow. The death toll exceeded 100 people.

Hurricane tornadoes in the Ivanovo, Yaroslavl and Kostroma regions on June 9, 1984 destroyed many buildings in cities and towns, broke communication and power lines, scattered groves, and destroyed many houses in rural areas. A tornado is almost always clearly visible, and a deafening roar is heard as it approaches. average speed travel is 50-60 km/h.

In January 1968, in the town of Jung (Sweden), an amazing incident occurred when, during a hockey match in an open area, a tornado with its edge picked up the goalkeeper of one of the teams along with the goal and lifted him several meters into the air. After hanging for some time, both the goalkeeper and the goal fell to the ground. The goalkeeper remained alive, but, of course, he was very scared.

The consequences of tornadoes are damage and destruction of buildings, power and communication lines, the formation of drifts and blockages on roads, destruction of agricultural crops, damage and loss of ships. As a result of these natural Disasters Animals die, people get injured and people die. People in hurricane and tornado zones are most often struck by flying objects and collapsing structures. A secondary consequence of hurricanes are fires that occur due to accidents on gas communications, power lines, and sometimes as a result of lightning strikes.

According to statistics, an average of 400 people die from tornadoes every year; and on March 18, 1925, about 700 people died in the states of Illinois, Missouri, Tennessee, and Kentucky (USA). In North Dakota in 1957, a tornado destroyed 500 buildings and caused losses of $15 million. In our country, the most memorable tornado hit the Ivanovo and Kostroma regions in 1984. He overturned cranes, lifted cars and carriages into the air, destroyed buildings like matches broke trees and even bent rails. railway. Its diameter reached 2 km.

The destructive effects of tornadoes are associated primarily with wind, but the subsequent phase of rainfall and flooding is much more dangerous. These phenomena acquire a formidable character and turn into rampant disasters with catastrophic consequences on the scale of entire states or even several countries in any geographical area. The main causes of death and injury to people are the destruction of buildings and falling trees.

Associated components of tornadoes: floods, storm surge.

As a result of tornadoes, the living conditions of the population are disrupted: utilities, transport, roads are damaged, Agriculture, there is a danger of intensification of bank destruction and landslide processes, telephone communications are interrupted and power supply is disrupted settlements with a population of tens and hundreds of thousands of people.

Almost the entire population may be temporarily resettled from the affected areas.

Particular caution for ministries and departments involved in eliminating the consequences of emergencies and disasters natural character, cause dangerous objects: hydroelectric power stations, nuclear power plants, chemical, biological, fire and explosion hazards, industrial, military warehouses and storage facilities. Social facilities: airports, train stations, transnational railways and car roads, Insurance companies, banks, strategic economic facilities and, most importantly, energy potential, on which the performance of the entire complex of urban infrastructure depends.

A tornado, in contact with the surface of the earth, often leads to the same degree of destruction as with strong hurricane winds, but over much smaller areas.

These destructions are associated with the action of rapidly rotating air and a sharp rise air masses up. As a result of these phenomena, some objects (cars, light houses, roofs of buildings, people and animals) can be lifted off the ground and transported hundreds of meters. This action of a tornado often causes the destruction of raised objects, and causes injuries and contusions to people, which can lead to death.

Measures to protect the population from tornadoes:

Timely forecast and warning of the population;
- reducing the impact of secondary damage factors (fires, dam breaks, accidents);
- increasing the stability of communication lines and power supply networks;
- preparation of shelters, basements and other buried structures for sheltering people;
- shelter in durable structures and places that provide protection for farm animals; provision of water and feed for them.

Reports of large-scale destruction caused by tornadoes arrive with enviable regularity. Moreover, these messages are becoming more and more frequent, and the consequences of the tornado are becoming more and more tragic. This is due both to the power of the tornado itself as a natural phenomenon, and to related factors. Since it is obvious that the consequences of equivalent tornadoes that formed in deserted areas or raged in densely populated areas will vary significantly.

A tornado is not a breeze

The peculiarity of a tornado and the reason for its impressive consequences is the fact that a tornado is actually a whole complex of powerful and fast tornadoes. The “engine” of a tornado becomes a funnel, in which the wind speed reaches its maximum values. In turn, a tornado funnel is a complex of several local tornadoes, which pull inside everything that comes across the path of this phenomenon. This is precisely what explains the seemingly irrational picture observed in the aftermath of the most powerful and large tornadoes.

It is obvious from photographs and video footage from the air that the “road” of a tornado is actually heterogeneous: there are separate “strips” in it. Houses standing nearby can be damaged so unevenly that only the foundation remains of one, while the other stands virtually undamaged. In this case, the energy of individual tornadoes that are part of a tornado is summed up and reaches enormous values. Scientists have calculated that the power of an average tornado is equal to the energy released during the explosion atomic bomb with a capacity of 20 kilotons. Of course, this is enough to destroy buildings, overturn trains, not counting cars and smaller objects. In addition, in areas where tornadoes form, strong electromagnetic fields, that leads to a large number electrical discharges, including ball lightning.

What can a tornado do?

Talking about the mechanism of action and energy potential of tornadoes may seem abstract and theoretical. It would be much more clear to give several historical examples of the consequences that tornadoes led to:

At the beginning of the last century, the tornado of 1913, one of the many tornadoes in the famous Tornado Alley, was actively covered in the American press. Journalists were particularly impressed by the examples of how selective a tornado can be. In one case, he carried off two horses, while the cart they pulled and the person on it remained unharmed. A similar story happened to a woman milking a cow - the animal was carried away by a tornado into the clouds, while the villager was not injured;

one of the most famous is the Tri-State Tornado, which struck Missouri, Illinois and Indiana in March 1925. This tornado traveled a path of more than 300 kilometers and destroyed absolutely everything over an area of ​​about 200 square kilometers. In this case, almost 700 people died, over two thousand were seriously injured;

in the summer of 1984, a destructive tornado passed through the Central European part of the USSR. In fact, on June 9, 1984, in the territory modern Russia There were three tornadoes, the most destructive of which was the so-called Ivanovsky. The wind speed in it reached 100 meters per second, the tornado passed through the vicinity of Ivanovo, destroying many buildings in various populated areas. As a result, approximately 60 people were killed and more than 800 were injured.

Why is a tornado scary?

In reality, the question of what exactly is dangerous about a tornado is not so trivial. Because without clear knowledge of the nature of the danger it is impossible to develop effective system precautions and protection - and health and life directly depend on this. A tornado, of course, is dangerous in itself - if a person is caught in a tornado in an open area, he may die simply from falling from high altitude. But still, the main danger of a tornado for humans lies in objects captured by the whirlwind and flying at high speed, formed during the destruction of buildings and structures.

The consequences of tornadoes

According to statistics, an average of 400 people die from tornadoes every year; and on March 18, 1925, about 700 people died in the states of Illinois, Missouri, Tennessee, and Kentucky (USA). In North Dakota in 1957, a tornado destroyed 500 buildings and caused losses of $15 million. In our country, the most memorable tornado hit the Ivanovo and Kostroma regions in 1984. He overturned cranes, lifted cars and carriages into the air, destroyed buildings, broke trees like matches, and even bent railroad tracks. Its diameter reached 2 km.

The destructive effects of tornadoes are associated primarily with wind, but the subsequent phase of rainfall and flooding is much more dangerous. These phenomena acquire a formidable character and turn into rampant disasters with catastrophic consequences on the scale of entire states or even several countries in any geographical area. The main causes of death and injury to people are the destruction of buildings and falling trees.

Associated components of tornadoes: floods, storm surge.

As a result of tornadoes, the living conditions of the population are disrupted: utilities, transport, roads are damaged, agriculture suffers, there is a danger of intensifying bank destruction and landslide processes, telephone communications are interrupted and the power supply to settlements with a population of tens and hundreds of thousands of people is disrupted.

Almost the entire population may be temporarily resettled from the affected areas.

Of particular concern to ministries and departments involved in eliminating the consequences of emergencies and natural disasters are dangerous objects: hydroelectric power stations, nuclear power plants, chemical, biological, fire and explosion hazards, industrial, military warehouses and storage facilities. Social facilities: airports, train stations, transnational railways and highways, insurance companies, banks, strategic economic facilities and, most importantly, energy potential, on which the performance of the entire complex of urban infrastructure depends.

Prevention and mitigation

Catastrophic tornadoes are rarely observed, so it is difficult to use a statistical approach to predict them. The general understanding is that tornadoes can occur in any area where they have occurred before, and appropriate precautions should be taken. If atmospheric observations are made and if a tornado is detected, appropriate warnings are issued.

Since the likelihood of a tornado occurring in any particular area is very low, when designing ordinary industrial and civil buildings and structures, loads from tornadoes are not taken into account by building codes (for economic reasons). Loads from tornadoes are taken into account when selecting sites for nuclear power plants both in Russia and abroad. This takes into account wind speed (wind pressure), change atmospheric pressure when a tornado passes over a structure, impacts from flying objects.

The destruction caused by tornadoes, like hurricanes, is determined by the pressure of the high-velocity head of the wind flow, but also by the explosive effect of the rapid drop in pressure at the center of the tornado. Reinforced concrete structures are usually tornado resistant. The best shelter from tornadoes are civil defense shelters, and in their absence, solid basements of buildings.

As tornado statistics show, the destructive impact of the elements extends not only to environment, but also poses a threat to human life. More detailed information can be found on Wikipedia.

When this phenomenon occurs at sea, it is usually called a tornado; on land, it is called a tornado. In some regions, for example in Europe, it is called a blood clot. The diameter of the air funnel can reach several hundred meters.

How to recognize a tornado

There is no exact description of what a tornado looks like. A natural phenomenon may have different shapes and size. Most often it resembles a sleeve or trunk. It is believed that the most dangerous occurrence a tornado when it is hidden behind a wall of rain, snow or dust. At such moments, even experienced meteorologists find it difficult to notice the impending danger. Despite numerous studies, the causes of tornadoes are not reliably known today.

Before a tornado can form, there needs to be a significant amount of cold air in contact with warm, moist air. Most often, a tornado is accompanied by precipitation. When energy is supplied, the destructive effect begins. Its main initiators are water vapor and solar radiation. When a funnel is formed, the air in it moves at a speed of 18 to 138 meters per second. The average speed of a tornado is 20–60 km/h.

After the warm and cold air reaches the same temperature, the tornado loses its power and gradually disappears.

How does a tornado appear and how does it disappear? It always happens unexpectedly. Tornado statistics confirm that this natural phenomenon can rage from several minutes to several hours.

There are two types of elements:

1. Occurs as a result of strong heavy rains, accompanied by thunder and .
2. It is formed as a consequence of other factors.

Tornadoes of the first type are considered more dangerous. Depending on the strength of the tornado, the following groups are determined:

• dust devils– lasting a maximum of two minutes, capable of carrying sand, pebbles, and small objects over a short distance;
• small short-acting tornadoes– have more destructive power, and their path can reach up to 1000 meters;
• small tornadoes of long duration– like the previous ones, only their actions can spread over several thousand meters;
• hurricane storms- have a strong destructive effect. Their path can stretch for several tens of kilometers.

The consequences of a tornado can be disappointing:

• objects falling into the center of a tornado, especially those with sharp corners, can cause severe injury to nearby people when rotating rapidly;
• broken or uprooted trees, destroyed buildings, downed lines - can leave residents of the affected area without electricity and communications for some time;
• a tornado can easily cause a flood or;
• when, during a strong tornado, a person finds himself inside a blood clot, he is able to lift the victim to the height of a ten-story building, which minimizes the victim’s ability to survive.

Tornado like a natural phenomenon, are observed in almost all parts of the globe. Only regions with arctic and subarctic climates are excluded.

Where do the elements occur most often?

Tornado statistics show that they most often strike the North American continent:

• central US territories;
• a little less often - the eastern states of America;
• the state of Florida, especially the part located near the Florida Keys. Tornadoes occur almost daily, from late spring to mid-autumn.

Europe is considered the second place where tornadoes occur, with the exception of the Iberian Peninsula. Part of Russia, located on European territory, also cannot avoid spontaneous manifestations. Less common tornadoes are observed in:

1. Eastern Argentina.
2. Western-eastern Australia.

Tornado "Camille"

One of the most strong tornadoes in the world is considered "Camilla". Although it formed on the west coast of Africa, most of the destruction fell on the United States. It swept across the states:

1. Mississippi.
2. Alabama.
3. Virginia.
4. Louisiana.

US tornado statistics note that then:

• 113 people died;
• 256 people missing;
• 8931 people were injured.

Almost 75% of tornadoes form in North America. On the central plains of the country, which are characterized by a flat surface, the average number of formations is about 700 per year. The territory is called “Tornado Valley”.

The most destructive tornadoes

In addition to Camille, the statistics of tornadoes highlight even more destructive ones in history. List of tornadoes by year:

• 1870– San Callisto or the Great Hurricane. Officially, about 22 thousand people were counted as dead. The tornado passed through parts of the Caribbean islands and Haiti. Its destructive power not only uprooted trees, but also tore off the bark. As a result, almost 95% of the structures were destroyed.
• 1900– Galveston, played out in Texas. As a result, approximately 6,000 people became victims of the tornado. About 370 residential buildings remained destroyed.
• 1970– Cyclone Flea raged in East Pakistan and West Bengal (India). The exact number of victims is unknown. According to assumptions - about half a million. Due to the amount of rainfall, many villages on the banks of the Ganges River were not only flooded, but also completely washed away.
• 1975– Nina is in China. The typhoon's force broke several dams, the first of which was Bankiao. The gushing water claimed the lives of 230 thousand people. The exact number of victims is unknown.
• 1992- Andrew. It struck in the northwestern part of the Bahamas, hitting south Florida and southwestern Louisiana. 26 deaths occurred during its action and 36 as a result of damage a little later.
• 1992– Iniki, which originated in Haiti. For an island with a small territory, the destructive power of a tornado has become. 6 residents died.
• 1998– Mitch, formed in the Atlantic Basin. It raged in Nicaragua, El Salvador and Honduras. Human victims were counted at 20 thousand. More than 1 million residents were left not only without a roof over their heads, but also drinking water and medicines, which in turn provoked a massive spread of infectious diseases.
• 2002- Kenna. The village of San Blas suffered the most. Although there were no casualties, the consequences were disappointing, since only a quarter of the buildings remained completely undamaged.
• 2005 year– Katrina, who amazed with her power East Coast U.S.A. Tornado statistics in the United States marked it as the most destructive disaster in the entire history of the country. Then most of New Orleans was flooded - approximately 80%, 1836 people died - 705. More than 500 thousand residents were left homeless.

In the history of the 20th century, the largest tornado in the world in terms of destruction occurred in America in 1999 (Oklahoma City). He raged for 1.5 hours. He was given the name "Monster". Fortunately, when the tornado peaked, residents were able to evacuate and reduce the number of casualties to a minimum.

Many people believe that tornadoes usually occur in the ocean, for example, during calm periods. This is confirmed by meteorologists, who noted that with an increase in temperature by one degree, the strength of a hurricane increases by 5%.

American tornadoes of the 21st century

The largest tornadoes on the American continent:

Based on the number of tornadoes formed, the years 04/3–4/1974 stand out. Over two days, 147 blood clots were observed, affecting 11 states in America, and one state was affected by a tornado in Canada.

Tornado statistics in Russia note that due to a gradual increase in air temperature, the number of tornadoes occurring has increased 1.5 times over 30 years. Meteorologists also predict that ocean typhoons will become even more destructive every year.

Disaster movies with tornadoes

Disaster stories are becoming increasingly popular in cinema. about tornadoes and tornadoes were no exception. List of the best films that you can watch online:

1. "Hurricane" (1979).
2. "Tornado" (1996).
3. "Chasing a tornado."
4. "The Horror of the New York Tornado."
5. "Ice Storm"
6. "Day of Disaster"
7. "Day of Disaster - 2".