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Risk of thunderstorms in the south-west of France. Ten departments have been placed on orange alert by Météo France. Objective, not to become a target for lightning. The advice of Dr. Gérald Kierzek, author of the book Have the right reflexes.
An energy of 200 kilowatt hours
Everyone knows it: the storm is formidable. In fact, this atmospheric phenomenon, characterized by a series of lightning and thunderclaps, can be incredibly violent, and cause a lot of damage.
A few figures: each year, 1 million lightning strikes strike France, affecting between 200 and 300 people. On average, there are around thirty deaths per year. Remember that the electrical energy produced by a flash is around 200 kilowatt hours.
Avoid going out if there is a risk of thunderstorm
True, lightning strikes mainly outdoors – with a number of impacts of up to more than 50,000 in an hour. But it is also most often unpredictable.
However, if the risk of strong thunderstorms is announced, before any outdoor activity, it is better to inquire about the local weather forecasts, which are finer and more precise. And this, even if the sky seems serene. And as soon as you start to hear thunder or rumble, the storm has started. It is therefore important to seek shelter as quickly as possible.
What are the safe places?
If you are surprised by the storm, while you are outside, it is absolutely necessary to take refuge in a safe place. To know :
- A closed building: stay away from windows, avoid touching metallic objects, which can be conductive, unplug electrical appliances and do not use your landline telephone, but rather your mobile. As a reminder, the bus shelter is not a good idea. It is open to any wind and does not offer sufficient protection.
- Your car provided that it is not a convertible, nor parked under a tree and that the roof is made of metal. If lightning strikes your vehicle, it will then function as a Faraday cage, that is, as a protective envelope that will divert the current into the ground.
If you don’t have a closed place or car nearby, in short, if you’re hiking in the middle of nature, just sit on your backpack, your feet together and your head resting on your knees. The goal is to avoid contact with the ground as much as possible in case lightning strikes near you. If you don’t have a bag to act as insulation, stay squatting with your head resting on your knees.
And if you are in a group, move away from each other by ten meters: the human body being a conductor, the lightning can pass from one person to another and cause several victims.
What are the places to absolutely avoid?
Even in an emergency, it is better to keep a cool head and not give in to panic, to avoid heading towards a place that will prove to be dangerous. But there are quite a few of them:
- Fields or flat land such as football stadiums;
- Under a tree. If lightning strikes, the tree will not protect you. In addition to receiving an electrical charge or attracting lightning, the tree or a branch can hurt you by falling on you;
- Caves and cavities, in the mountains. They are not good shelters. On the contrary, they draw lightning inside;
- Water points, plains and rock faces.
False good ideas
- Run with long strides;
- Shelter under an umbrella. It is by definition above your head and is a metallic object that can attract and conduct lightning to you. Place it next to you;
- Take shelter in a phone booth. Indeed, if the overhead line of this cabin is struck by lightning, the overvoltage can spread through the cables and reach the person who has taken refuge inside;
- Swimming under a storm: for obvious reasons, this idea should be avoided, even if it is very hot! If lightning strikes your pool water when you’re swimming, you risk a lot. It is even the most dangerous risk.