The Science of Thunder and Lightning
How Thunderstorms Form
Thunderstorms develop early in the day when the sun heats the air near the ground. These pockets of warm air then rise and create cumulus clouds. As the air continues to heat, the clouds grow tall into vertical cumulus and rain develops. When the cloud becomes anvil shaped, a thunderstorm is practically inevitable.
How Lightning Forms
While these storms are forming, air acts as an insulator between the positive and negative charges in the cloud and between the cloud and the ground. When the difference in charges becomes too great, this insulating capacity of the air breaks down. Then, there is a rapid discharge of electricity. This is lightning.
It’s important to note that lightning comprises two different discharges. Cloud-to-ground bolts happen between charges in the cloud and the ground. In-cloud bolts occur between opposite charges within the thunderstorm cloud. A combination of both cloud-to-ground and in-cloud discharges is total lightning.
How Thunder Forms
The electrical discharge makes a loud noise we know as thunder. When lightning strikes through the air it heats it up quickly. This causes the air to expand rapidly and creates the sound of thunder. According to the National Weather Service, you can hear thunder about 10 miles from lightning strikes.