Dry storms are a strange meteorological phenomenon. The sky darkens and thunders, but it doesn’t seem to rain.

Imagine a thunderstorm with thunder and frightening lightning, but not a single drop of rain falls. The dark clouds are threateningly popping over a landscape already affected by the days of extreme heat, while lightning runs through the sky without expected rain.

This is not the scenario of a science fiction film, but the reality of dry thunderstorms, one of the most dangerous weather events of our time, according to Euronews.

These events, which may seem harmless due to the lack of rain, are actually one of the main natural causes of forest fires worldwide.

Their misleading character hides a complex chain of atmospheric processes that, in combination with the increasingly frequent and more intense heatwaves caused by climate change, convert huge areas of the planet into gunpowder warehouses waiting for a spark.

What are dry storms? The paradox of the electric heaven

Dry storm is a meteorological phenomenon characterized by the presence of intense electrical activity accompanied by little or no rainfall reaching the ground.

This definition contains a fundamental paradox: the term “dry” only describes the effect on the surface of the Earth and not the process that takes place inside the cloud of the storm.

In terms of atmospheric physics, all storms are initially liquid phenomena. They are formed by the condensation of water vapor and create precipitations inside them, like any conventional storm. The critical difference lies in what is happening with this rain as it descends to the ground.

In a dry thunderstorm, the precipitations formed in the upper layers meet, during their descent, a layer of extremely dry and warm air at the lower and medium levels. This “invisible barrier” causes full evaporation of rain drops or quartz crystals before reaching the ground.

The most characteristic visual feature is the “Virga”, filaments or precipitation curtains hanging at the base of the clouds but disappear in the air before reaching the ground. This phenomenon, known in the converse-ghost, is visible proof of a potentially very dangerous storm.

These thunderstorms are characterized by significant thunderstorms with intense lightning and thunder, little or no superficial precipitations, the presence of Virga and violent gusts of wind, known as “blowdowns”, which can exceed 100 km/h.

Heat waves are the perfect fuel for dry storms

The relationship between dry storms and heat waves is not just a meteorological coincidence, but a dangerous synergy that creates the perfect conditions for large -scale natural disasters.

The heat waves act catalytically on two fundamental fronts. On the one hand, they perform atmospheric preparation: Intense and persistent heat creates strong instability in the lower layers of the atmosphere, creating strong upward currents that supply the formation of stormy clouds. At the same time, high temperatures create this characteristic vertical structure with very hot air on the surface and a layer of dry air at the middle levels – the perfect recipe for evaporation of rain before reaching the ground.

They also transform the landscape in a potentially deadly way. Days or weeks of extreme heat and low humidity dehydrate vegetation, dry the soil and reduce forest humidity to critical low levels. This process converts the area into a real “barrel” that only needs a spark to ignite.

The interaction between these phenomena can create particularly dangerous vicious circles. Unlike wet thunderstorms, which provide thermal relief with rain and cold currents, dry thunderstorms do not interrupt heat pressure.

In extreme cases, they can cause “thermal bursts” or strong downward currents that are heated quickly due to compression, leading to sudden increases in temperatures above 10 ° C within minutes, often accompanied by blind winds.

The global warming intensifies this dangerous synergy. A warmer atmosphere holds more water vapor, exacerbating the entire hydrological cycle. This results in more heavy rainfall in some areas, but also faster evaporation. In areas that are prone to drought, such as the Mediterranean, this leads to more intense droughts and more flammable landscapes.

Modeling shows that climate change will make heatwaves more frequent, intense and longer, creating the ideal conditions for dry thunderstorms that will become the new summer regularity.

The many risks of a seemingly harmless dry storm

Lack of rainfall in dry thunderstorms can create a delusional sense of safety, which can prove to be fatal. Behind their seemingly harmless appearance lies a chain reaction of interconnected risks much more severe than they seem.

The most immediate and destructive risk is dry lightning, the thunderbolts from the clouds to the soil that occur without natural rain protection. The lightning can heat the air surroundings of up to 30,000 ° C, and when it hits the previously dried vegetation, the ignition is almost instantaneous.

In a wet storm, the subsequent rain often extinguishes these small fireplaces before spreading. In a dry storm, the fire is free to install and grow. Single fires can also burn late for hours or days without visible flame, to suddenly break out when the weather changes.

Dry thunderstorms can also create tornado, strong downward currents capable of creating straight line winds exceeding 120 km/h. Dry storms occur when the air is cooled due to the evaporation of the Virga, while the hot thunderstorms result from the heating of the gases through the compression as they descend.

These strong winds can uproot trees, cause damage to infrastructure and, in fire conditions, quickly rejuvenating flames and causing explosive spread of fire.

The third significant risk is the serious deterioration of air quality. Strong winds can stir huge quantities of dust and sand, creating dust storms that reduce visibility to zero and carry particles dangerous to the respiratory system. Fires starting with dry lightning also create smoke loaded with particularly dangerous microparticles, capable of entering the bloodstream.

This smoke can travel hundreds of kilometers, affecting the quality of air in cities far from the original fire.

The real danger lies in the way these threats are linked to each other: the lightning ignings the fire, the strong winds that blow it escalate into a fiery storm and together launch a quality crisis of air that can last for weeks and affect millions.

Spain experienced a clear example of this phenomenon in 1979, in the Ayora-Eubera region (Valencia). During a strong heat, a fire caused by dry lightning destroyed about 44,000 hectares. This remains a historical depiction of the devastating chain reaction that climate change is increasingly turning into a new reality for vulnerable areas such as the Mediterranean.