- Education and Science
Facts about Lightning that You Should Know
Lightning is a bolt of electric current that is caused by the sudden discharge of electric charges from cloud to cloud or from cloud to the ground. It occurs during a thunderstorm or even when there is the clear weather.
You can never predict when lightning is going to strike so when you see a burst of lightning in the sky take necessary precautions and be safe.
What you should do when lightning strikes
Lightning can strike miles ahead and cover a large width of an area where it occurs. The key to avoiding being struck by lightning is to avoid being in areas where it can strike.
When you hear a thunderstorm and see lightning the safest place to take cover would be indoors.
- if you are out walking to a destination or working outside in your garden and see lightning in the sky head for cover
- go inside your home, office or any nearby building
- if you are shopping, do not get out of the mall and stay inside
- if you are inside a car, then stay inside without touching the metal parts of your car because metal can conduct electricity
What you should know about staying indoors to protect yourself when lightning strikes
A house that follows all safety standards will be well grounded so that the electric current is safely transmitted to the ground without injuring anyone in the house.
Even when you are inside and the house is well-grounded lightning can still injure you because lightning takes the secondary paths available in your house to reach the ground like the electrical wiring, metal frameworks, plumbing, cable, telephone lines, antennas.
Make sure that you are actually safe from lightning strikes indoors by doing the following -
- do not take a bath or wash your hands during a thunderstorm with lightning. Stay away from water pipes and faucets
- do not stand in basements, patios or in any place that has excess moisture because these areas are direct grounding paths to lightning currents
- do not use any wired appliances or devices like your washing machine, TV, dishwasher
- do not stand under or near stand alone trees or tall objects because positive electric charges accumulate on these objects and are direct paths for lightning strikes
If proper lightning protection system is installed in the house then the dangers due to lightning strikes can be avoided.
Here is the reason why -
The lightning protection system will safely conduct the electric current caused due to lightning directly to the ground without damaging the structure or anything inside the house.
Are you safe from a lightning when you are inside the car?
If you are inside a car when lightning strikes then stay inside the car but keep your hands off the doors, windows or any metal frame structures in your car because metals are good conductors of electricity. Also, remember not to touch any wired devices in your car.
When the lightning hits your car, it travels over the metal frame and jumps over the tyres to hit the ground, and you are safe if your are not touching any metal parts of the car or using any wired devices inside the car.
Structures that do not offer protection against lightning
The following do not offer protection against lightning strikes -
- golf carts
- bus shelters
- small outdoor shelters
If you are outdoors when lightning strikes stay away from tall objects that stand alone like trees, flag poles, metal fences or any metallic objects that can attract current directly.
Any building that has proper lightning protection system installed is safe from the dangers of a lightning strike.
Sky-scrappers are protected from lightning strikes by lightning protection systems.
How does lightning occur?
When water on the ground is heated it evaporates and rises up as water vapor. As it rises it condenses into tiny particles of water that gather to form clouds. The water droplets in higher levels of the clouds condense into tiny particles of ice because the temperature is colder when compared to the lower portions of the cloud.
Many clouds can join together to form bigger clouds loaded with water and ice. The small ice particles constantly bump against each other due to forces of wind and develop positive and negative charges.
Positive charges are concentrated on the top of the cloud and the negative charges that are lighter gathers at the bottom of the cloud. When this happens the positive charges on the ground are attracted towards the negative charges at the bottom of the clouds.
The ground electrical charges concentrate on tall objects such as a single tree, pole or mountain. The negative charges escape from the cloud and try to reach the positive charges on the ground and when they connect lightning strikes the ground.
What is thunder?
When lightning strikes from the cloud to the ground it pierces through the surrounding air and opens up an empty channel for a second. Once the lightning fades the air collapses back into the channel causing a huge sound wave that we hear as thunder.
- Intracloud lightning occurs when the lightning strikes within a cloud. This happens when both the positive and negative charges are in the same cloud.
- Intercloud lightning is lightning that occurs between two clouds. This happens when positive charges are in one cloud and the negative charges in the other cloud. This type of lightning is very rare.
- Forked lightning has many small branched lightning streaks. It can be seen as intercloud or intracloud lightning, or it can just jump from the cloud into the thin air.
- Sheet lightning is a blinding flash that covers a large are of the sky and seems to light up all the clouds within range.
- Ribbon lightning occurs when the wind separates a lightning bolt, and it appears as two parallel lightning strikes.
- Ball lightning appears as a huge red ball that explodes with a loud noise. This form of lightning is very rare,
- Blue-Jets are bright colored flashes that occur high above thunderstorms. They are also called Red Stripes or Green Elves. Blue-Jets cannot be seen from the ground.
Calculating the Distance from a Thunderstrom
There is a way to calculate how far away the thunderstorm is from you -
- count the seconds between the time that you see the lightning and hear the thunder
- divide the seconds by five
The number that you get is how far away the storm is from you in miles.
Point to Note
One thing to remember is that a person who is struck by lightning does not retain electric charges so you can go ahead and touch the person.
Call for help immediately if a person is struck by lightning.