Summer means thunderstorms and lightning for most of us. The people at the Norwegian research organization SINTEF have put together a list of tips on what you should do – and not do – in thunderstorms, published in their own magazine Norwegian SciTech News.
As a general rule, lightning will take the path of least resistance on its way to the ground. So, if it strikes a metal conductor, it will follow that, says Oddgeir Rokseth at SINTEF Energy Research to the magazine. – This could, for example, be the cables supplying electricity to your house. Cables exposed to the air are particularly vulnerable. The voltage will then be conducted into your house via the installation.
Rokseth says it’s less of an issue in cities and towns with electrical cables buried underground, but he still warns against touching power lines or water pipes inside your house during thunderstorms.
Lightning strikes cause major damage worldwide every year, but it’s thankfully rare for people to be hurt or killed – there’s a reason for the phrase “struck by lightning”.
The researchers at SINTEF offer 8 tips for what you should – and shouldn’t – do during a thunderstorm to stay safe:
1. Unplug your TV and other gadgets! A strike anywhere in the distribution grid may generate over-voltages that subsequently follow the grid to reach your house. SINTEF says modems, in particular, are very prone to lightning damage, and they recommend unplugging both the internet cable and power cord.
2. Stick to your cellphone! Landline/wired phones are also at risk of over-voltages resulting from lightning strikes. Do not charge your cellphone, keep it unplugged.
3. Install surge protection! If you are afraid of damage to electrical equipment in your house, you can install surge protection.
4. Don’t go swimming or bathe! According to the researchers, a lightning strike that hits water can distribute electricity of several thousand amperes through the water. They also recommend against bathing in bathtubs, as lightning strikes can follow water pipes into the house.
5. The car will keep you safe! The car’s metal body will ensure that a lightning strike is passed onto the ground, and not into your body. Houses offer similar protection, although wooden and brick houses are much less than ones made from concrete.
6. Don’t shelter under large trees and avoid open landscapes! There is a greater risk of lightning striking objects that stand out in the landscape. The researchers also point out that being wet when struck by lightning is a benefit, as the water will conduct the current outside your body and reduce the risk of internal injuries. Drop using an umbrella or holding on to anything made of metal.
7. Seek cover on a mountain trip! The researchers say it’s rare – and incredibly bad luck – to get struck by lightning while hiking, but they still recommend people seeking shelter and preferably head back down.
8. Lay down if you’re on a boat! The researchers recommend heading to shore as the best option, but if you’re unable to then avoid touching the mast, go under the deck, or lay low if the boat is open.
You can easily tell how close the lightning is to you by counting the time from the flash until you hear the thunder. A five-second delay means the lightning struck around one mile (1.6 kilometers) from you, as the speed of sound is around 1100 feet (330-350 meters) per second (depending on temperature and moisture). A three-second delay would thus mean the lightning struck one kilometer (0.6 miles) from your own location.