How does lightning form?
Rapidly rising air in a thunderstorm interacts with rapidly falling air within the thunderstorm to create separately positive and negative charged areas within the cloud. Air acts as an insulator, but when the charge builds up to a level that exceeds its ability to act as an insulator, the result is a spark we see as lightning. The lightning equalizes the positive and negative charged areas. Several types of lightning are common: * In-cloud lightning extends from one charged region of a cloud to another * Cloud-to-cloud lightning extends between two clouds * Cloud-to-air lightning extends from a cloud to the air, not touching the ground * Cloud-to-ground lightning stretches from a cloud to the ground There are two ways of looking at lightning’s direction: 1. Upward streamers: Lightning starts in a cloud when there is an updraft reaching subfreezing temperatures. A cloud-to-ground flash starts at around 15,000 feet during summer in the US. It travels toward the ground in 50-yard steps –
