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