During heatwaves, dry thunderstorms pose a major threat to French forests. Unlike conventional thunderstorms, these phenomena are not accompanied by significant rainfall, but produce lightning and violent gusts of wind. These conditions are conducive to the outbreak and rapid spread of forest fires.
Why are they so dangerous?
Lack of rain : Dry thunderstorms do not produce enough water to extinguish fires or dampen vegetation that has already been dried out by the intense heat.
Frequent lightning strikes : Electrical discharges can directly set vegetation alight or cause sparks on infrastructure (power lines, fences).
Strong winds : Gusts of wind fan the flames and cause them to spread more quickly, making the fires more difficult for firefighters to bring under control.
An increased risk during heatwaves
Prolonged heatwaves dry out vegetation, turning it into ideal fuel. When dry thunderstorms strike, the conditions are right for spontaneous fires and large-scale wildfires. In 2022, several major fires in Gironde and the Landes were attributed to this phenomenon.
How can you protect yourself?
The authorities are reminding the public of the importance of complying with the fires are prohibited during high-risk periods and to report any sightings of smoke promptly to the emergency services (18 or 112). Public vigilance is essential to limit the impact of these events.
A challenge for the fire brigade
Fire services are adapting their strategies in response to these risks by stepping up aerial surveillance and deploying preventative measures. However, the combination of heatwaves and dry thunderstorms remains a scenario that teams on the ground dread.