Meteorological emergencies are dangerous natural processes and phenomena that occur in the atmosphere under the influence of various natural factors or their combinations, which have or may have a damaging effect on people, farm animals and plants, economic facilities and the natural environment.

Meteorological emergencies include:

• meteorological phenomena associated with the movement of air in the atmosphere;
• meteorological phenomena associated with high and low temperatures;
• meteorological phenomena associated with precipitation;
• meteorological phenomena associated with the deposition of ice and sticking of wet snow on electrical wires;
• meteorological phenomena associated with the formation of ice on the roads;
• fog.

Meteorological phenomena associated with the movement of air in the atmosphere include:

• strong wind- movement of air relative to the earth's surface with a speed or horizontal component of more than 14 m/s;
• vortex- atmospheric formation with rotational movement of air around a vertical or inclined axis;
• Hurricane- wind of destructive force and considerable duration, the speed of which exceeds 32 m/s. Hurricane Katrina began forming on August 23, 2005 in the Bahamas. The wind speed during the hurricane reached 280 km/h. On August 27, 2005, the hurricane passed over the coast of Florida near Miami and turned towards the Gulf of Mexico. The most severe damage was caused to New Orleans in Louisiana, where about 80% of the city's area was under water. The disaster killed 1,836 people;
• cyclone- an atmospheric disturbance with low air pressure and hurricane wind speeds that occurs in tropical latitudes and causes great destruction and loss of life. The local name for a tropical cyclone is typhoon;
• storm - prolonged very strong wind with a speed of more than 20 m/s, causing severe waves at sea and destruction on land;
• tornado - a strong small-scale atmospheric vortex with a diameter of up to 1000 m, in which the air rotates at a speed of up to 100 m/s, which has a great destructive force (Fig. 8.8). A tornado is the most dangerous natural phenomenon associated with the movement of air in the atmosphere;
• flurry - a sharp short-term wind force up to 20–30 m/s and higher, accompanied by a change in its direction and associated with convective processes;
• dust storm- the transfer of large amounts of dust or sand by strong winds, accompanied by a deterioration in visibility, blowing the topsoil along with seeds and young plants, falling asleep crops and highways. In case of a dust storm, you should cover your face with a gauze bandage, a scarf, a piece of cloth, and your eyes with glasses.

Rice. 8.8.

Meteorological phenomena associated with high and low temperatures include:

• hard frost- this is a meteorological phenomenon, when the expected and observed negative anomalies of average daily air temperatures in November - March are from -10 to -25 ° C for at least 5 days and more or the minimum air temperature is close to extreme values;
• heatwave is a meteorological phenomenon when the expected and observed positive anomalies of average daily air temperatures in May-August for at least 5 days are +27°C or more, or the maximum air temperature is close to extreme values.

In the summer, a dangerous agrometeorological phenomenon can occur - drought. Drought- this is a complex of meteorological factors in the form of a prolonged absence of precipitation, combined with high temperature and a decrease in air humidity, leading to a violation of the water balance of plants and causing their inhibition or death.

Severe frost and heat are dangerous for the life and health of people, adversely affect their ability to work, and damage agriculture and industry. Also during such periods, the fire hazard increases. Long-term and extreme low temperatures pose a particular danger to public utilities due to freezing of water supply pipes on the streets and in buildings, which leads to a lack of water supply and water heating in people's homes.

High and low temperatures can be accompanied by strong winds. In winter, blizzards are dangerous. heavy blizzard- this is the transfer of snow above the ground by wind at a speed of more than 15 m / s and visibility of less than 500 m. A snowstorm is possible in combination with snowfall, which leads to a deterioration in visibility and skidding of transport routes.

In winter, the effect of the cooling force of the wind on the human body should be taken into account (Table 8.3).

In strong snowstorms and low temperatures, it is undesirable to move outside settlements. You can lose your bearings and freeze. The car can only move on major roads and highways. When leaving the car, do not leave it out of sight.

Table 8.3

The influence of the cooling force of the wind on the human body

Wind force, m/s

Temperature, °С

temperate zone

Growing danger zone

Dangerous zone

Meteorological phenomena associated with precipitation include the following.

Grad - precipitation falling during the warm season in the form of particles of dense ice with a diameter of 5 mm to 15 cm, usually together with heavy rain during a thunderstorm. Large hail is considered to be ice particles with a diameter of more than 20 mm. Strong hail is dangerous for human life and health, it can destroy crops, damage the roofs of buildings, vehicles.

Downpour (heavy rain)- this is short-term precipitation of great intensity, usually in the form of rain (rain with snow). Heavy rain is considered to be precipitation of 50 mm or more in 12 hours or 30 mm or more in 1 hour. Long-term heavy showers are precipitation of 100 mm or more in 2 days. Heavy rains can cause floods, flooding of streets, mudflows, and impede traffic.

Heavy snowfall - this is a prolonged intensive snowfall (20 mm of precipitation or more in 12 hours), leading to a significant deterioration in visibility and difficulty in traffic.

Meteorological phenomena associated with the formation of ice and sticking of wet snow to electrical wires pose a danger to power supply, which can lead to wire breaks and disruption of power supply to settlements and regions. Such cases happen in Russia, in particular, on the Black Sea coast of the Caucasus, in the Stavropol Territory, etc. Broken wires pose a danger to human life.

Ice- this is a layer of dense ice that forms on the earth's surface and on objects when supercooled drops of rain or fog (melted and then refrozen snow) freeze. Ice is dangerous for pedestrians and vehicles.

If the weather forecast indicates ice or icy conditions, measures should be taken to reduce the likelihood of injury, prepare low-slip shoes, attach metal heels or foam rubber to the heels, and stick adhesive tape on dry soles, you can rub the soles of shoes with sandpaper.

You should move carefully, slowly, stepping on the entire sole. In this case, the legs should be slightly relaxed, hands free. If you slip, you should

crouch to reduce the height of the fall. At the time of the fall, it is necessary to group up, and, rolling, soften the blow to the ground.

Fog - meteorological phenomenon, the accumulation of condensation products in the form of drops or crystals suspended in the air directly above the earth's surface, accompanied by a significant deterioration in visibility. Heavy fog is fog with a visibility of less than 100 m. Due to heavy fog, car accidents can occur, and airplanes cannot land at airports.

What are hazardous weather events?

The glow of fire on the horizon. During the spring and half of the summer of 2016, 1.4 million hectares of forest burned down in Russia, which caused damage in the region of three billion rubles. Photo: extremeinstability.com

According to Roshydromet, the number of dangerous meteorological phenomena is increasing year by year. 2015 set a dismal record of 571 extreme weather events, more than in any of the previous 17 years, the agency said in a report. What are dangerous weather phenomena, what they are and what they threaten - in the article of the Climate of Russia portal.

As Russia's climate becomes more maritime and less continental as a result of warming, the number of hazardous phenomena that cause damage increases, says the head of the climatology department of the All-Russian Scientific Research Institute of Hydrometeorological Information - World Data Center (VNIIGMI-WDC) Vyacheslav Razuvaev.

Number of severe weather events recorded between 1998 and 2015. Roshydromet data

According to the definition of Roshydromet, hazardous meteorological phenomena are natural processes and phenomena that occur in the atmosphere and / or near the surface of the Earth, which, in terms of intensity, scale and duration, have or can have a damaging effect on people, agriculture, economic facilities and the environment.

In other words, extreme weather always threatens well-being, health and life. To predict dangerous phenomena, Roshydromet has developed criteria - according to them, experts determine the degree of danger of an impending or already occurring disaster. A total of 19 weather phenomena have been identified that may pose a serious threat.

Element number 1: wind

Very strong wind (at sea - a storm). The speed of the elements exceeds 20 meters per second, and with gusts it increases by a quarter. For high-altitude and coastal areas, where winds are more frequent and intense, the standard is 30 and 35 meters per second, respectively. Such weather causes the fall of trees, elements of buildings and free-standing structures, such as billboards, breaks in power lines.

A strong wind can not only break umbrellas, but also cut wires. Photo: volgodonsk.pro

In Russia, Primorye, the North Caucasus and the Baikal region suffer from storms more often than other regions. The strongest winds blow in the Novaya Zemlya archipelago, the islands of the Sea of ​​Okhotsk and in the city of Anadyr on the edge of Chukotka: the air flow speed often exceeds 60 meters per second.

Hurricane- the same as a strong wind, but even more intense - with gusts, the speed reaches 33 meters per second. During a hurricane, it is better to be at home - the wind is so strong that it can knock a person down and cause injuries.

Trees felled by the 1998 hurricane near the walls of the Kremlin. Photo: Alexander Putyata / mosday.ru

On June 20, 1998, in Moscow, wind gusts reached 31 meters per second. Eight people became victims of bad weather, 157 sought medical help. 905 houses were de-energized, 2157 buildings were partially damaged. The damage to the city economy was estimated at one billion rubles.

Squall- wind speed of 25 meters per second, not weakening for at least a minute. It poses a threat to life and health, can damage infrastructure, cars and houses.

Tornado in Blagoveshchensk. Photo: ordos / mreporter.ru

Tornado- a vortex in the form of a pillar or cone, heading from the clouds to the surface of the Earth. On July 31, 2011, in Blagoveshchensk in the Amur Region, a tornado overturned three trucks, damaged more than 50 support poles, roofs of houses, non-residential buildings and broke 150 trees.

A meeting with a vortex can be the last in life: inside its funnel, the speed of air flows can reach 320 meters per second, approaching the speed of sound (340.29 meters per second), and the pressure can drop to 500 millimeters of mercury (the norm is 760 mm Hg). st). Caught in the range of this powerful "vacuum cleaner" objects rise into the air and rush through it at great speed.

Most often, tornadoes are found in tropical latitudes. The type of vortex depends on what it has absorbed into itself. So, water, snow, earth and even fiery tornadoes are distinguished.

frost called a temporary decrease in the temperature of the soil or air near the ground to zero (against the background of positive average daily temperatures).

If such a meteorological phenomenon occurs during the period of active vegetation of plants (in Moscow it usually lasts from May to September), agriculture will be damaged, up to the complete destruction of the crop. In April 2009, in Stavropol, frost losses were estimated at almost 100 million rubles.

hard frost registered when the temperature reaches a dangerous value. Each region usually has its own. In Nizhny Novgorod on January 18, 2006, the temperature dropped to minus 35 degrees Celsius, as a result of which 25 people sought medical help in one day, of which 21 were hospitalized with frostbite.

If in the period from October to March the average daily temperature is seven degrees below the long-term norm, then the abnormal cold. Such weather leads to accidents in housing and communal services, as well as to the freezing of agricultural crops and green spaces.

Element number 2: water

Heavy rain. If more than 30 millimeters of rain fell in an hour, such weather is classified as a heavy downpour. It is dangerous because the water does not have time to go into the ground and drain into the rain sewer.

In August 2016, Moscow was flooded twice, and each time it led to serious consequences. Photo: trasyy.livejournal.com

Heavy rains form powerful streams that paralyze traffic on the roads. Washing away the soil, water masses bring down metal structures to the ground. In hilly or ravine-dissected areas, heavy rainfall increases the risk of mudflows: water-saturated soils sag under their own weight - entire slopes slide down, burying everything that comes in their way. And this happens not only in the mountains and hilly areas. So, on August 19, 2016, as a result of a prolonged downpour, mudflow blocked traffic on Nizhniye Mnevniki Street in Moscow.

If at least 50 millimeters of precipitation falls in 12 hours, meteorologists classify this phenomenon as " Very heavy rain”, which can also lead to the formation of mudflows. For mountainous areas, the critical indicator is 30 millimeters, since the likelihood of catastrophic consequences is higher there.

A powerful mud stream with fragments of stones is a mortal danger: its speed can reach six meters per second, and the “head of the elements”, the leading edge of the mudflow, is 25 meters in height. In July 2000, a powerful mudflow hit the town of Tyrnyanz in Karachay-Cherkessia. 40 people were missing, eight were killed, eight more were hospitalized. Residential buildings and infrastructure of the city were damaged.

Continuous heavy rain. Precipitation that fell within half or a whole day should exceed the mark of 100 millimeters, or 120 millimeters in two days. For rainy areas, the norm is 60 millimeters.

Landslide after prolonged heavy rain in Moscow. Photo: siniy.begemot.livejournal.com

The probability of flooding, flushing and convergence of mudflows during prolonged heavy rain increases dramatically. To combat the elements in large cities, networks of drainage collectors have been laid. They are designed on the basis of long-term rainfall data, but climate change, leading to an increase in the amount of rain, often prepares unpleasant surprises. With frequent and prolonged showers, sewage sewers need regular inspections and cleaning. Soil and debris from construction sites especially clog the drainage system, said the mayor of Moscow Sergei Sobyanin, commenting on the flooding of the capital on August 19, 2016.

Very heavy snow. This type of dangerous phenomenon means heavy snowfall, as a result of which more than 20 millimeters of precipitation falls in 12 hours. This amount of snow blocks roads and makes it difficult for cars to move. Snow caps on houses and structures can bring down individual elements and break wires with their weight.

In March 2016, as a result of a heavy snowfall, traffic in the capital was paralyzed, and cars in the yards were covered with snow. Photo: drive2.ru

On the night of March 1-2, 2016, Moscow was covered with 22 millimeters of snow. By message service "Yandex.Traffic", in the first half of the day there were nine-point traffic jams on the roads. Dozens of flights were canceled due to the rampant disaster.

hail It is considered large if the diameter of the ice balls exceeds 20 millimeters. This weather phenomenon poses a serious danger to property and human health. Hailstones falling from the sky can damage cars, shatter windows, destroy vegetation, and destroy crops.

Stavropol city broke all local records and at the same time the cars of the townspeople. Photo: vesti.ru

In August 2015, hail hit the Stavropol Territory, accompanied by heavy rain and wind. Eyewitnesses filmed on smartphones hailstones the size of a chicken egg and a diameter of five centimeters!

strong blizzard called a weather phenomenon in which for half a day the visibility from flying snow is up to 500 meters, and the wind speed does not drop below 15 meters per second. During the rampage of the elements, driving becomes dangerous, flights are canceled.

During the snowstorm that covered Moscow in December 2012, the opposite side of the street was not visible, and the whole city was in traffic jams. Photo: rom-julia.livejournal.com

Intense snowfall often leads to traffic accidents and many kilometers of traffic jams. On December 1, 2012, the media reported that after a long snowfall in Moscow, motorists spent the night right in their cars, and traffic jams stretched for 27 kilometers on the M10 highway in the Tver region. Drivers were provided with fuel and hot meals.

Heavy fog, or haze, are the conditions under which for 12 hours or more visibility is from five to zero meters. The reason for this may be a suspension of tiny drops of water with a moisture content of up to one and a half grams of water per cubic meter of air, soot particles and tiny ice crystals.

In heavy fog, visibility is only a few meters. Photo: PROMichael Kappel / Flickr

Meteorologists determine atmospheric visibility using a special technique or using a transmissometer device. Reduced visibility can provoke traffic accidents and block the operation of airports, as was the case in Moscow on March 26, 2008.

Strong ice. This weather phenomenon is recorded by a special device - an icing machine. Among the characteristic features of this bad weather are ice from 20 millimeters thick, wet, non-melting snow 35 millimeters high, or frost half a centimeter thick.

Ice provokes many accidents and leads to casualties. On January 13, 2016, in Tatarstan, this meteorological phenomenon caused a series of accidents in which dozens of cars were damaged.

Element number 3: earth

Dust storm It is recorded by meteorologists when, for 12 hours, dust and sand carried by the wind at a speed of at least 15 meters per second impair visibility at a distance of up to half a kilometer. On April 29, 2014, a dust storm raged for several hours in the Irkutsk region. The element partially disrupted the power supply of the region.

A storm in the Irkutsk region covered the region with dust« cap." Photo: Alexey Denisov / nature.baikal.ru

Dust storms are common in regions with dry, hot climates. They disrupt the movement of cars and block air traffic. Sand and small stones flying at high speed can injure people and animals. After the passage of such storms, it is necessary to clear roads and premises from sand and dust, as well as to restore agricultural land.

Element number 4: fire

Abnormal heat It is recorded by meteorologists when in the period from April to September for five days the average daily temperature is seven degrees above the climatic norm of the region.

The UN Office for Disaster Risk Reduction noted that from 2005 to 2014, more than 7,000 people died from the effects of heat waves. 2016 set a new world temperature record - 54 degrees in Mithrib, Kuwait. For Russia, the maximum remains 45.4 degrees in Kalmykia, which were recorded on July 12, 2010.

Heatwave- the temperature exceeds the established dangerous threshold in the period from May to August (the critical value for each territory is different).

This leads to droughts, increased fire risk and heat stroke. On August 8, 2016, in Chelyabinsk, where the temperature did not fall below 32 degrees for a week, 25 people with symptoms of overheating sought medical help. Six of them were hospitalized. Agricultural losses amounted to 2.5 million rubles.

Extreme fire hazard. This type of dangerous phenomenon is declared at high air temperature, associated with a lack of precipitation.

Fires are a real scourge of protected nature, annually destroying 0.5 percent of the world's forests. Photo: Gila National Forest / Flickr

— Digest of the main events of the Year of Ecology-2017

- . What did the metaphysical journey through the Russian North lead to?

Lecture

Natural emergencies and measures to reduce the possible impact from them

1. Theoretical provisions

2. Natural phenomena of meteorological origin

3. Natural phenomena of geophysical origin

4. Natural phenomena of geological origin

5. Natural phenomena of cosmic origin

6. Natural phenomena of biological origin

Theoretical Provisions

Natural emergencies have threatened the inhabitants of our planet since the beginning of civilization. The amount of damage depends on the intensity of natural phenomena, the level of development of society and living conditions. Natural phenomena can be extreme, extraordinary and catastrophic. Catastrophic natural phenomena are called natural disasters. Disaster is a catastrophic natural phenomenon that can cause numerous human casualties and cause significant material damage. The total number of natural disasters worldwide is constantly increases. Natural phenomena most often sudden and unpredictable and also they can wear explosive and fast paced. Natural phenomena can happen regardless from each other (for example, avalanches and wildfires) and during interaction(eg earthquake and tsunami). Mankind is not so helpless in the face of the elements. Some phenomena can be predicted, and some can be successfully resisted. To effectively counteract natural emergencies, it is necessary to know composition of the event, historical chronicle and local characteristics of natural hazards. Protection from natural hazards can be active(for example, construction of engineering structures) and passive(the use of shelters, hills. Due to the occurrence of natural phenomena, they are currently divided into six groups.

Natural phenomena of meteorological origin

Meteorology is the science that studies changes in the Earth's atmosphere. These are temperature, humidity, atmospheric pressure, air currents (wind), changes in the Earth's magnetic field. The movement of air relative to the earth is called wind. Wind strength is estimated on a 12-point Beaufort scale (at a standard height of 100 meters above an open flat surface).

Storm - long and very strong wind, the speed of which exceeds 20 m/s.

Hurricane - wind of great destructive power and considerable duration, the speed of which is 32 m/s (120 km/h). A hurricane-force wind accompanied by heavy rainfall is called a typhoon in Southeast Asia.

Tornado - or tornado - an atmospheric vortex that occurs in a thundercloud, and then spreads in the form of a dark sleeve or trunk towards the land or sea surface. The principle of operation of a tornado resembles the operation of a vacuum cleaner.

dangers for people during such natural phenomena are the destruction of houses and structures, overhead power lines and communications, ground pipelines, as well as the defeat of people by fragments of destroyed structures, glass fragments flying at high speed. During snow and dust storms, snow drifts and accumulations of dust on fields, roads and settlements, as well as water pollution, are dangerous. The movement of air is directed from high pressure to low pressure. An area of ​​low pressure is formed with a minimum in the center, which is called cyclone. The cyclone in diameter reaches several thousand kilometers. The weather during a cyclone is cloudy, with an increase in wind. Weather-sensitive people during the passage of a cyclone complain of a deterioration in well-being.

Very coldy - characterized by a decrease in temperature for several days by 10 or more degrees below the average for the area.

Ice - a layer of dense ice (several centimeters) that forms on the surface of the earth, sidewalks, the carriageway of streets and on objects and buildings when supercooled rain and drizzle (fog) freeze. Ice is observed at temperatures from 0 to 3 C. As an option - freezing rain.

Black ice - This is a thin layer of ice on the surface of the earth, formed after a thaw or rain as a result of a cold snap, as well as freezing of wet snow and raindrops.

Dangers. Increase in the number of accidents and injuries among the population. Violation of life activity during icing of power lines, contact networks of electric transport, which can lead to electrical injuries and fires.

Blizzard(blizzard, blizzard) is a hydrometeorological disaster. Associated with heavy snowfall, with wind speeds above 15 m/s and snowfall duration of more than 12 hours

dangers for the population consist in drifts of roads, settlements and individual buildings. The drift height can be more than 1 meter, and in mountainous areas up to 5-6 meters. It is possible to reduce visibility on the roads to 20-50 meters, as well as the destruction of buildings and roofs, breaks in power transmission and communications.

Fog - the accumulation of small water droplets or ice crystals in the surface layer of the atmosphere, reducing visibility on the roads.

dangers. Reduced visibility on the roads disrupts the operation of transport, which leads to accidents and injuries among the population.

Drought - prolonged and significant lack of precipitation, more often at elevated temperatures and low humidity.

Heatwave - characterized by an increase in the average annual temperature of the ambient air by 10 or more degrees for several days

To predict dangerous phenomena, Roshydromet has developed criteria - according to them, experts determine the degree of danger of an impending or already occurring disaster. A total of 19 weather phenomena have been identified that may pose a serious threat.

Element #1: Wind

Very strong wind(at sea - a storm). The speed of the elements exceeds 20 meters per second, and with gusts it increases by a quarter. For high-altitude and coastal areas, where winds are more frequent and intense, the standard is 30 and 35 meters per second, respectively.

In Russia, Primorye, the North Caucasus and the Baikal region suffer from storms more often than other regions. The strongest winds blow in the Novaya Zemlya archipelago, the islands of the Sea of ​​Okhotsk and in the city of Anadyr on the edge of Chukotka: the air flow speed often exceeds 60 meters per second.

Hurricane- the same as a strong wind, but even more intense - with gusts, the speed reaches 33 meters per second. During a hurricane, it is better to be at home - the wind is so strong that it can knock a person down and cause injuries.

The hurricane on May 29 of this year in Moscow was the largest in terms of the number of victims in the last hundred years. During the hurricane on May 29, the wind speed in some areas of the capital reached 25 m/s. More than 10 people died, more than a hundred were injured.

Squall- wind speed of 25 meters per second, not weakening for at least a minute. It poses a threat to life and health, can damage infrastructure, cars and houses.

Tornado- a vortex in the form of a pillar or cone, heading from the clouds to the surface of the Earth. On July 31, 2011, in Blagoveshchensk, Amur Region, a tornado overturned three trucks, damaged more than 50 support poles, roofs of houses, non-residential buildings, and broke 150 trees.

A meeting with a vortex can be the last in life: inside its funnel, the speed of air flows can reach 320 meters per second, approaching the speed of sound (340.29 meters per second), and the pressure can drop to 500 millimeters of mercury (the norm is 760 mm Hg). st). Caught in the range of this powerful "vacuum cleaner" objects rise into the air and rush through it at great speed.

frost called a temporary decrease in the temperature of the soil or air near the ground to zero (against the background of positive average daily temperatures).

hard frost registered when the temperature reaches a dangerous value. Each region usually has its own.

If in the period from October to March the average daily temperature is seven degrees below the long-term norm, it means that abnormal cold. Such weather leads to accidents in housing and communal services, as well as to the freezing of crops and green spaces.

Element number 2: water

Heavy rain. If more than 30 millimeters of rain fell in an hour, such weather is classified as a heavy downpour. It is dangerous because the water does not have time to go into the ground and drain into the rain sewer. Heavy rains form powerful streams that paralyze traffic on the roads. Washing away the soil, water masses bring down metal structures to the ground. In hilly or ravine-dissected areas, heavy rainfall increases the risk of mudflows.

If at least 50 millimeters of precipitation falls in 12 hours, meteorologists classify this phenomenon as "Very heavy rain", which can also lead to the formation of mudflows. For mountainous areas, the critical indicator is 30 millimeters, since the likelihood of catastrophic consequences is higher there.

Powerful mud stream with fragments of stones is a mortal danger: its speed can reach six meters per second, and the “head of the elements”, the front edge of the mudflow, is 25 meters in height.

In July 2000, a powerful mudflow hit the town of Tyrnyanz in Karachay-Cherkessia. 40 people were missing, eight were killed, eight more were hospitalized. Residential buildings and infrastructure of the city were damaged.

Continuous heavy rain. Precipitation that fell within half or a whole day should exceed the mark of 100 millimeters, or 120 millimeters in two days. For rainy areas, the norm is 60 millimeters.

The probability of flooding, flushing and convergence of mudflows during prolonged heavy rain increases dramatically.

Very heavy snow. This type of dangerous phenomenon means heavy snowfall, as a result of which more than 20 millimeters of precipitation falls in 12 hours. This amount of snow blocks roads and makes it difficult for cars to move.

hail It is considered large if the diameter of the ice balls exceeds 20 millimeters. This weather phenomenon poses a serious danger to property and human health. Hailstones falling from the sky can damage cars, shatter windows, destroy vegetation, and destroy crops.

In August 2015, hail hit the Stavropol Territory, accompanied by heavy rain and wind. Eyewitnesses filmed on smartphones hailstones the size of a chicken egg and a diameter of five centimeters!

strong blizzard called a weather phenomenon in which for half a day the visibility from flying snow is up to 500 meters, and the wind speed does not drop below 15 meters per second. During the rampage of the elements, driving becomes dangerous, flights are canceled.

Heavy fog or mist, are the conditions under which for 12 hours or more visibility is from five to zero meters. The reason for this may be a suspension of tiny drops of water with a moisture content of up to one and a half grams of water per cubic meter of air, soot particles and tiny ice crystals.

Meteorologists determine atmospheric visibility using a special technique or using a transmissometer device.

Heavy ice. This weather phenomenon is recorded by a special device - an icing machine. Among the characteristic features of this bad weather are ice from 20 millimeters thick, wet, non-melting snow 35 millimeters high, or frost half a centimeter thick.

Ice provokes many accidents and leads to casualties.

Element number 3: earth

Dust storm It is recorded by meteorologists when, for 12 hours, dust and sand carried by the wind at a speed of at least 15 meters per second impair visibility at a distance of up to half a kilometer.

Element number 4: fire

Abnormal heat It is recorded by meteorologists when in the period from April to September for five days the average daily temperature is seven degrees above the climatic norm of the region.

The UN Office for Disaster Risk Reduction noted that from 2005 to 2014, more than 7,000 people died from the effects of heat waves.

Heatwave- the temperature exceeds the established dangerous threshold in the period from May to August (the critical value for each territory is different).

This leads to droughts, increased fire risk and heat stroke.

Extreme fire hazard. This type of dangerous phenomenon is declared at high air temperature, associated with a lack of precipitation.

Dangerous meteorological phenomena- these are natural processes and phenomena that occur in the atmosphere, which, by their intensity (strength), scale of distribution and duration, have or can have a damaging effect on people, farm animals and plants, economic objects and the natural environment.

These phenomena include:

1. Very strong wind

The average wind speed is not less than 20 m/s, on the coast of the seas and in mountainous areas not less than 25 m/s. Instantaneous wind speed (gust) not less than 25 m/s, on the coast of the seas and in mountainous areas not less than 30 m/s.

A sharp short-term increase in wind. Instantaneous wind speed (gust) over 25 m/s for at least 1 minute.

A strong small-scale atmospheric vortex in the form of a pillar or funnel, directed from a cloud to the surface of the earth

4. Heavy rain

Heavy rain shower. The amount of liquid precipitation is not less than 30 mm for a period of not more than 1 hour

5. Very heavy rain

Significant liquid and mixed precipitation (rain, heavy rain, sleet, snow with rain). The amount of precipitation is not less than 20 mm for a period of not more than 1 hour

6. Very heavy snow

Significant solid precipitation (snow, heavy snow, etc.). The amount of precipitation is not less than 20 mm for a period of not more than 12 hours.

7. Continuous heavy rain

Rain continuous (with interruptions no more than 1 hour) for several days. The amount of precipitation is not less than 120 mm for a period of at least 2 days.

8. Large hail

Hailstone diameter over 20 mm

9. Strong snowstorm

A general or blowing blizzard with strong winds, causing a significant reduction in visibility. Average wind speed not less than 15 m/s, MWD not more than 500 meters

10. Strong dust storm

The transport of dust or sand in high winds, causing a severe deterioration in visibility. The average wind speed is not less than 15 m/s, MWD is not more than 500 meters.

11. Heavy fog

Fog with a significant reduction in visibility. MDV no more than 50 meters

12. Icy frost deposits

Strong deposits on the wires of street lighting (icing machine). Diameter, mm, not less than: Ice 20, Complex deposit 30, Wet snow 35, Hoarfrost 50.

13. Extreme heat

High maximum air temperature for a long period of time. The maximum air temperature is not less than 35°C for 5 days.

14. Hard frost

Low minimum air temperature for a long time. The minimum temperature is not more than -35°C for 5 days.

In addition to HH, there are also hydrometeorological phenomena that significantly impede or hinder the activities of individual enterprises and sectors of the economy, but do not reach the HH criteria in terms of their values. The criteria for these phenomena are developed taking into account the division by strength and intensity specified in RD 52.27.724-2009 "Manuals on short-term weather forecasts for general purposes", developed, approved and put into effect on 01.03.2010 by Roshydromet. Hydrometeorological phenomena are selected depending on the type of activity of a particular enterprise, organization or sector of the economy and refer to the types of specialized hydrometeorological services.* (data from the hydrometeorological center of the Russian Federation)