During the rainy season throughout the year or in places where weather conditions are unstable, thunderstorms are likely to occur. These natural phenomena, in addition to looking like a distant sound and light show, can cause serious damage to our electrical installations.
Understanding how thunderstorms form and what effects they have is crucial to protecting our equipment and ensuring the continuity of our services in buildings, homes, offices or manufacturing plants.
What are thunderstorms?
Thunderstorms are meteorological phenomena that, due to the discharge of large amounts of static electricity accumulated in clouds, can cause damage to electricity systems or in the worst case, forest fires, short circuits or death to people and animals that are struck by lightning.
During a thunderstorm, lightning manifests itself as large flashes of light, known as lightning. The air around the lightning heats up and expands rapidly, generating sound waves called thunder. Because light travels faster than sound, we first see the lightning and then hear the thunder.
Types of thunderstorms
Due to their composition of various air types, temperature and humidity levels, thunderstorms can be classified into four main broad categories:
- Single-cell thunderstorms: made up of a single thunderstorm cell, they are generally weak, short-lived and do not draw on additional energy. They produce lightning, thunder, hail and heavy rain, but their impact is usually limited.
- Multicell storms: Composed of two or more cells, these storms are more intense and longer lasting and can cause significant damage. They are often accompanied by strong wind or hail and can result in brief floods and tornadoes.
- Supercell storms: these are the most intense and dangerous storms, known for their ability to produce tornadoes. They are fuelled by a circuit of updrafts that sustain their energy for many hours and can travel great distances, causing significant destruction with their hurricane-force winds.
- Turbulence lines: These are extensive lines of active storms that can span hundreds of kilometres. They are characterised by hurricane-force winds and torrential rains, and often have a common storm front that can cause devastation across large areas.
Causes of thunderstorms
The formation of thunderstorms develops in three main phases, each influenced by specific factors:
- Birth and moisture: this cumulus phase, the mass of moisture rises into the atmosphere and clouds begin to grow. Warm, moist air is crucial for the formation of these storm clouds. Without sufficient moisture, the clouds would not reach the mass necessary to trigger a thunderstorm.
- Maturity and atmospheric instability: at this stage the cloud continues to grow vertically to form a cumulonimbus, and within this type of cloud, downdrafts are generated, causing heavy precipitation. Internal turbulence produces lightning throughout the cloud.
- Dissipation and lifting mechanisms: In this final phase, clouds begin to disperse and warm surface air is replaced by cold air. Downdrafts predominate here and precipitation progressively weakens until it ceases. Factors such as mountains or convection caused by solar heating can act as mechanisms that lift moist air.
Consequences of thunderstorms
Among the major hazards of thunderstorms are the following:
- Lightning strikes are the main threat during a thunderstorm, as they can impact objects and people, causing serious injury or even death. They also have the potential to start fires and damage electrical devices due to the enormous amount of energy they release.
- Flooding from torrential rainfall, which in turn poses a risk to areas prone to flash flooding.
- Hail damage, sometimes thunderstorms also bring hail, which can cause damage to crops, vehicles and structures.
What to do before a thunderstorm?
It is not necessary to wait for a thunderstorm to arrive before taking the necessary measures to protect electrical systems, household appliances, or high energy consuming equipment in factories.
The first and most important thing is to have lightning arresters located at the highest part of a building and a standardised and properly maintained grounding system. Lightning rods are metallic devices, in the form of a pointed rod, which deflect lightning into the grounding system, thus protecting the structure and internal equipment from electric shock.
In addition, it is advisable to install surge protection systems (SPDs) in the main electrical panel. These devices help prevent voltage spikes, caused by lightning strikes, from damaging electrical appliances and electronic equipment.
What to do during a thunderstorm?
It is important to stick to the emergency plan and keep people away from windows and doors, avoid using landline telephones and electrical appliances, and do not take shelter under trees or metal structures outdoors.
Unplugging electrical and electronic devices during the storm is also a prudent measure to protect them from damage.
Do not handle metal tools or objects. Avoid contact with water, especially at beaches, rivers or lakes, as salinity can increase the danger of electric shocks.
What to do after a thunderstorm?
When a thunderstorm passes, it is important to follow some precautions:
- Check for property damage or downed power lines and contact insurance companies, emergency services and power companies.
- Wait for instructions from the authorities, as it is not advisable to go outside immediately, as there could be downed wires or flooding.
- Help others with first aid if someone has suffered electrical burns or with cardiopulmonary resuscitation if the person has been struck by lightning.
