How Does Lightning Form?
Lightning is an electrical current and occurs within thunderclouds, or cumulonimbus clouds. In these clouds, small pieces of ice collide into each other creating an electrical charge. After a while, the cloud fills up with electrical charges. Positive electrical charges form at the top of the cloud and negative electrical charges form at the bottom of the cloud, closest to the surface of the Earth.
On the ground, a positive electrical charge builds up on the ground and concentrates around things that stick up, such as mountains, houses, telephone poles and trees. The positive charge streams up from the ground and connects with negative charge reaching down from the cloud (opposites attract!) creating the lightning strike!
Take the Earth Gauge Kids quiz to learn how thunder is created!
All images courtesy of NOAA.
Learn More about Lightning!
- You can determine how far away a thunderstorm is by doing math! Start off by counting the number of seconds between a flash of lightning and the next boom of thunder. Once you have that number, divide it by five to determine the distance to the lightning in miles. For example, if you count 10 seconds between a flash of lightning and the next boom of thunder, the thunderstorm is about two miles away.
- Lightning can strike up to 10 miles away from a storm! Always remember “When Thunder Roars, Go Indoors!” Take cover immediately when you hear thunder or see lightning!
- Sometimes lightning will give you a few seconds of warning before it strikes. For example, your hair will stand on end, your skin will tingle, palms get sweaty or a metallic taste in your mouth. Yuck!
Both images courtesy of NOAA.