What is a storm? The answer is simple in the questions that registered the largest increase in searches made by Brazilians on Google last year.
When it rains in Brazilian cities like São Paulo, interest in the topic is renewed with each new precipitation forecast.
A growing body of research shows that Brazilians have a lot of skepticism about how storms develop and everyday situations, such as whether you should use a cell phone or take a shower.
Check out the most frequently asked questions on Google below, with answers from experts interviewed by BBC News Brazil on one of the most popular topics of the Brazilian summer.
1. What is a storm?
A storm is a meteorological phenomenon that “is characterized by strong winds, rain, thunderstorms, lightning, hail and lightning,” explains Climate Professor at the Federal University of Uberlândia (UFU), Paulo César Méndez.
In other words, it is an intense rain accompanied by lightning or hail; Storms are not considered thunderstorms without at least one of these events.
Storms form in large vertical clouds Cumulonimbus.
Moderate rain forms in the clouds Cirrus (Fiber, tall, white and thin) or Layer (Low clouds are slightly lower in the sky.)
The type of cloud that forms determines the intensity of the rain, the time it takes to fall and consequently whether it is a storm or not.
2. How do storms form? What causes thunderstorms?
Although they are different questions, they are similar and the answers complement each other. So, let's answer them together.
A storm is a meteorological phenomenon characterized by multiple atmospheric instabilities that cause the molecules of the Earth's surface to move with more force, causing the formation of clouds.
They are formed from the movement of air in an area of low atmospheric pressure.
“Storms are mainly associated with the meeting of two air masses with different characteristics (warm/dry and humid/cold) that cause a temperature variation in the atmosphere. This collision causes an intense movement of molecules on the surface of the atmosphere. The Earth and that agitation,” explains Rafael de Ávila Rodríguez, professor and climatologist at the Institute of Geology of the Federal University of Catalonia (UFCAD).
“That is, warm air (less dense) rises in the atmosphere, while cold air (higher density) descends towards the earth's surface, which reduces atmospheric pressure,” explains the climatologist.
“It is this collision between air masses that causes a storm.”
3. How do storms occur?
A storm is a meteorological phenomenon characterized by atmospheric instability, that is, when the sky “shakes.”
Instability occurs when molecules on Earth's surface move too strongly, causing clouds to form.
They are formed from the movement of air in an area of low atmospheric pressure.
“Storms are mainly associated with the meeting of two air masses with different characteristics (warm/dry and humid/cold), which causes a variation in temperature in the atmosphere,” explains Rafael de Ávila Rodríguez, professor and climatologist at the Institute of Geography. . from the Federal University of Catalonia (UFCAT).
“That is, warm air (less dense) rises in the atmosphere, while cold air (higher density) descends towards the earth's surface, which reduces atmospheric pressure,” explains the climatologist.
“It is this collision between air masses that causes the storm because it causes the molecules to move violently and this agitation,” he says.
4. How long will the storm last?
The duration of the storm varies from a few minutes to several hours.
The determining factor is whether or not hail (snow) falls. Hail showers are more common on very hot days.
It occurs when warm air from the Earth's surface meets very cold clouds at high points in the atmosphere. A sudden change in temperature causes water droplets to solidify and form hail. Glaciers form in clouds of large vertical size and are called Cumulonimbus.
When these clouds cannot support the weight of the glaciers inside them, they all collapse at once and form hail.
Mendes explains that storms with hail usually last between 10 and 30 minutes.
“Because the cloud forms and quickly releases all its energy in the form of a storm,” says the UFU professor.
Other types of storms that do not include hail develop in clouds that spread over large areas and dissipate slowly, lasting from an hour to an entire afternoon, Mendes adds.
“It is precisely this large accumulation of water that can cause problems such as flooding and flooding.”
5. What to do in case of a thunderstorm?
Lightning is an atmospheric electrical discharge that originates in a cloud and strikes the ground or another cloud.
It is formed within vertical clouds, which cause storms, from the attraction between the opposite charges (positive and negative) present in them.
The positive charges are at the top of the cloud and the negative charges are at the bottom. This difference in charge creates a lightning bolt, which releases this charge of energy, which can reach the ground.
Thunder is the sound produced when this discharge of energy (lightning) travels through the air. Lightning is electromagnetic radiation produced by the plasma created in the air when the lightning (discharge) passes through it; Some of this radiation is visible light, that is, the “heat” we see in the sky.
It is recommended not to stay in open areas during thunderstorms. The best thing you can do is always protect yourself.
“The first is to seek shelter in a property or in a car,” Mendes says.
But, if this is not possible, there is a way to reduce the risks of lightning strikes, for example by staying away from trees.
“You should avoid taking shelter under trees because lightning usually travels a very short distance between the cloud and the ground,” says the climatologist.
“In this case, it is recommended that the person sit or lie on the ground to prevent the body from becoming a lightning rod.”
6. Can I use my cell phone during a storm?
Experts interviewed by BBC News Brazil say that the risk of using a cell phone during a storm really depends on the situation each person is in.
“If you are in a safe environment, inside your house or car, and your cell phone is not plugged in, there is no problem using the device,” explains Mendes.
But if a person has the device plugged in, the expert's recommendation is not to use it or unplug it from the outlet to use it.
“Lightning can strike this power grid and reach your device, causing an accident like an electric shock,” says the UFU professor.
It is recommended not to use the device in open, exposed environments or at high altitudes such as mountains and hills, as it may become a lightning rod and cause electric shock.
7. Can I shower during a storm?
According to experts, the risk of bathing depends on the type of bathroom a person has at home.
An electric shower, as its name suggests, is a conductor of energy.
During storms, it is generally not recommended to use or come into contact with electrical equipment.
“If lightning strikes the electrical grid and is not blocked by the circuit breakers in the house, it can strike the shower and electrocute anyone who is there,” explains Mendes.
This electrical shock can cause skin burns or cardiac arrest and even death from electrical shock.
However, if the shower is not connected to the mains electricity, provided by the heater, there is no problem using it during storms.
8. What is the difference between a storm and a hurricane?
Although they may seem like different phenomena, thunderstorms and thunderstorms are similar, explain experts interviewed by BBC News Brazil.
“The words are similar, they refer to a very strong meteorological phenomenon with lightning, lightning, thunder, wind and heavy rain,” says Mendes.
“You can have heavy rain and call it a storm, or, from the same heavy rain, call it a thunderstorm.”
The popular Brazilian language has no shortage of synonyms for storm. You've probably heard terms like flood, world-ending rain, or downpour.
9. Why are storms named after people?
In fact, hurricanes are named after people.
Hurricanes are very strong tropical cyclones; The designation is used only for hurricanes that form from the North Atlantic to the Northeast Pacific.
Hurricanes (and hurricanes) are broader phenomena than storms. These are large areas of the atmosphere that form a low pressure center that helps form large storm clouds.
In a sense, hurricanes and tornadoes can be understood as a storm system.
For an event to be classified as a hurricane, winds must reach 119 km/h.
Hurricanes that affect the northwest Pacific Ocean are also called hurricanes.
According to the US military, the use of human names instead of numbers or technical terms is intended to avoid errors and confusion.
For example, names are easier to remember when issuing an alert.
The lists of names are created by the World Meteorological Organization (WMO), an agency of the United Nations (UN).
“For this reason, every year a list is made with the names corresponding to the letters of the alphabet, and that list must be followed,” explains Rodríguez.
The names given to these events, such as Hurricane Otis, which hit Acapulco, Mexico, in late October 2023, can be feminine or masculine.
