Lightning strikes over Clontarf on December 9 2014. Picture: Jacob Grams Source: Supplied

Yes, you can be struck by lightning and yes, there are things you can do to avoid a potentially fatal shock. Here’s what you should know:

THREE STRIKES

There are three ways you can be stuck by lightning. The first, most obvious, is being directly hit. This is rare and fatal.

The most common way people are affected are through ground currents. This is when a nearby object, such as a tree, is struck and the current is carried through the ground and then to you.

Dr Rohan Jayaratne, a research fellow at Queensland University of Technology, said there is also the side flash, when lightning travels from an object through the air to you.

If this happens, you’ll feel a shock, be thrown to the ground and your muscles will spasm. This is common for people who stand near an object and could be fatal depending on the magnitude of the flash.

Dr Jayaratne, who has experienced a side flash while researching in Botswana, said the body aches for about a week afterwards. Also, if you shelter under a tree, the lightning current can jump to you so don’t seek a tree shelter during a storm.

Storms have battered Sydney and Brisbane this week, with lightning a nightly feature. Picture: AAP Image/NEWZULU/BRODIE FARREN. Source: Getty Images

THE WEATHER

Lightning is caused by charges in thunder clouds that contain ice particles. The hail or snow crystals rub against each other, causing friction, and this generates the charge. The top half of the cloud becomes positive and the bottom half negative.

“When this charge builds up you can have a spark between the top and the bottom, or between the bottom and the ground,” Dr Jayaratne said.

If the spark is caused by the negative charge from the bottom of the cloud to the ground, the lightning is called a `ground flash’. It’s this type of lightning that causes damage.

However, 75 per cent of lightning flashes occur within the cloud, and are called an `intra-cloud flash’.

This is when the spark is from the top of the cloud to the bottom of the cloud, and when you see a cloud light up, but no strike.

Lightning strikes over Liverpool in Sydney. The SES advises people not to speak on landline phones as the current can travel through lines. Source: Supplied

THUNDER FRIEND

Lightning leads to thunder. The heat of the lightning channel causes the surrounding air to rapidly expand, which in turn creates a shock wave. This shock wave is what you hear as thunder.

Light travels faster than sound, which is why you’ll always see lightning before you hear thunder. You can tell how far the lightning is from you by measuring the time between the lightning and the thunder. If they both happen at the same time, the lightning is directly overhead.

TOP TARGETS

Lightning is attracted to the tallest objects in the vicinity of the storm. It’s believed the Empire State Building is struck 17 times a year.

Metallic objects are more likely to attract lightning along with trees, because of their height and especially when they’re wet. “The moisture on the surface of the bark conducts the current to the ground, so it’s more likely to get hit when it’s wet,” Dr Jayaratne said.

It’s more common in tropical places, closer to the equator. Picture: Helen McGowan Source: News Corp Australia

COMMON PLACE

Lightning is more common the closer you are to the equator. When the ground around the equator becomes hot, the air expands and rises, creating thunderstorms high in the atmosphere.

A US astronaut caused an online storm after posting this Vine of a lightning storm on Earth, as seen from the ISS. Courtesy: Vine/Reid Wiseman

The tropical weather also creates moisture in the air, and when this moisture or water vapour travels toward the cloud, it condenses into water and can then turn into ice. The ice then interacts and create the lightning.

The taller the thunderstorm, the more intense the lightning, Dr Jayaratne said.

This is referred to as the ‘latitude effect’. But it’s not the only factor that governs the global distribution of lightning. There is also the `land-sea effect’.

Although oceans cover 75 per cent of the earth’s surface, 70 per cent of lightning occurs over land. This is due to surface heating. It means the best lightning storms happen over large land masses close to the equator.

It’s no surprise then that Darwin in the Northern Territory is a lightning hot spot, along with Africa and the Amazon.

However, the highest lightning intensity in the world is in Rwanda, which is on the equator and home to tropical forests that create a lot of air moisture.

The Brisbane sky gets lit up last week. Picture Peter Wallis Source: News Corp Australia

CAUGHT OUT

There are steps you can take if you’re caught outside during a lightning storm.

Being inside a house is fairly safe, because if lightning strikes the house it will be conducted down the pipes to the ground.

If you are at home, avoid touching any metal that’s connected to the ground. Don’t shower, and you also shouldn’t use a landline phone because power lines can carry the current through the line. One of the safest places to be during a storm is inside a car, which acts as a `Faraday cage’.

A Faraday cage is a conductor that limits the current to its edges. Because a car has a metal body, the current doesn’t penetrate into the middle where it’s safe for you to sit.

“So if lightning hits the car, it will safely conduct to the ground outside. It won’t go to the inside,” Dr Jayaratne said. If you’re in an open space, with no cars or buildings around, Dr Jayaratne advises lying flat on the ground so you’re not the tallest object in the area. You definitely don’t want to be playing golf.

“If lightning decides to hit that area it would go for the highest point and it would pick you out,” he noted.

“But if you’re swinging a club, that could be even worse.”

WHAT TO REMEMBER IN A LIGHTNING STORM

• Avoid the outdoors if possible

• Don’t shelter under a tree

• Don’t stand near a street light or similar tall object

• Don’t carry an umbrella

• Don’t play golf

• Don’t use a landline phone or have a shower

• If stuck in an open space, lie on the ground