Never Shower During a Thunderstorm. A Physicist Explains Why

Several yellow thunderstorm warnings have been issued for the UK by the Met Office.

It's important to know how to stay safe during a storm because your chances of being struck by lightning are low. About 24,000 people are killed each year by lightning in the world.

People are familiar with basic thunderstorm safety, such as avoiding standing under trees or near a window, and not speaking on a corded phone.

Did you know that you shouldn't take a shower, a bath, or wash the dishes during a storm?

You need to know how lightning works to understand why.

There are two basic elements that cause a storm to grow: water and warm air. The high temperatures and humidity creates large amounts of moist air that can form into a storm.

There are millions of water and ice droplets in the clouds. The falling ice drops are passed a negative charge by the rising water drops.

Clouds act as Van de Graaff generators in a storm, creating huge charge separations inside the clouds.

The opposite charge in the ground is what attracts a lighting strike towards the ground. The storm discharges between positive and negative regions in order to balance its charges.

metal is more likely to be struck during a storm because it is the one of least resistance.

Go indoors when thunder roars, it's the most useful advice for a storm. This doesn't mean that you're safe from the storm. Staying in the storm can be riskier than some activities inside.

Path of least resistance

You're not likely to be struck by lightning if you're sitting in a bath outside or showering in the rain. The electricity would follow the path of least resistance if lightning struck your house.

Water in your pipes provides a convenient path for electricity to follow to the ground.

Water and metal can be found in the shower, which makes it an ideal path for electricity to travel.

That shower could be turned into something else. The US Centers for Disease Control and Prevention encourages people to avoid all water-based activities during a storm to reduce their risk of getting hit.

There are dangers to watch out for during a storm. One is leaning on a wall. If metal beams are reinforced with concrete, they can provide a path for lightning.

The pathways for the lightning strike to take are provided by plugged in electrical outlets, so don't use them.

If you can hear thunder in the distance, you are close enough to the storm to catch lightning even if there is no rain.

Ten miles away from the parent storm, there can be lightning strikes.

Half an hour after the last thunderclap is a good time to return to the shower. You don't want to end up with part of the fireworks whenThunderstorms like to save a big one for the end.

James is a physics lecturer at the university.

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