Lightning is a discharge of electricity caused by imbalances between storm clouds and the ground, or within the clouds themselves. Lightning occurs commonly during thunderstorms as well as other types of energetic weather systems. Here are the steps that lead to lightning:

• Static charges: Lightning begins as static charges in a rain cloud. Winds inside the cloud are very turbulent. Water droplets in the bottom part of the cloud are caught in the updrafts and lifted to great heights where the much colder atmosphere freezes them. Meanwhile, downdrafts in the cloud push ice and hail down from the top of the cloud. Where the ice going down meets the water coming up, electrons are stripped off, resulting in a cloud with a negatively charged bottom and a positively charged top.

• Electric fields: These electrical fields become incredibly strong, with the atmosphere acting as an insulator between them in the cloud. When the strength of the charge overpowers the insulating properties of the atmosphere, lightning happens.

• Discharge: As the negative charge gets close to the ground, a positive charge, called a streamer, reaches up to meet the negative charge. The channels connect and we see the lightning stroke. We may see several strokes using the same path, giving the lightning bolt a flickering appearance, before the electrical discharge is complete.

Thunder is the sound made by a flash of lightning. When lightning heats the air around it to incredible temperatures, as hot as 54,000 °F (30,000 °C), the heated air expands explosively, creating a shockwave as the surrounding air is rapidly compressed and then expands again.