What causes lightning?

Question

Why does it happen during a strorm?

Answer 1

Lightning is produced in thunderstorms when liquid and ice particles above the freezing level collide, and build up large electrical fields in the clouds. Once these electric fields become large enough, a giant "spark" occurs between them, like static electricity, reducing the charge separation. The lightning spark can occur between clouds, between the cloud and air, or between the cloud and ground. As in the photo above, cloud-to-ground lightning usually occurs near the boundary between the updraft region (where the darkest) clouds are, and the downdraft/raining region (with the lighter, fuzzy appearance). Sometimes, however, the lightning bolt can come out of the side of the storm, and strike a location miles away, seemingly coming out of the clear blue sky. As long as a thunderstorm continues to produce lightning, you know that the storm still has active updrafts and is still producing precipitation. The temperature inside a lightning bolt can reach 50,000 degrees F, hotter than the surface of the sun. Objects that are struck by lightning can catch on fire, or show little or no evidence of burning at all.

Answer 2

read this article below for complete information

Answer 3

There are droplets of water in clouds that drop through the clouds. As the droplets "rub against" the clouds, electrons are rubbed off of the droplets onto the clouds. Imagine millions of these droplets which are now positively charged after giving up their electrons that land on the ground and make the ground enormously positively charged. Pretty soon the cloud will say, "Hey, I have too many electrons and I'm about to spill them on the ground!!" That spill is lightining

Answer 4

No one really knows for sure, but one theory that make sense to me would be the strong convection currents in a Thunderhead or a Supercell.

As the currents flow up and down the storm, positive and negative ions form and accumulate in different parts of the storm.  And you know what happens when that occurs... lightning. Its just the flow of electrons from one part of the cloud to the other, or to the ground. If you watch a lightning bolt in slow motion, you can see that the lightning travels in both directions essentially completing the circuit, this is evidence that different parts of the cloud consist of different charges.

Again, no one knows for sure why these ions accumulate in different parts of the cloud.