The Beauty of Lightning

A Brilliant Electric spark discharge in the atmosphere, occurring within seconds.. Scientists and the public have given names to these various types of lightning.

[Intracloud lightning, sheet lightning, anvil crawlers]
Intracloud lightning is the most common type of lightning, and occurs completely inside one cumulonimbus cloud; it is termed sheet lightning because the bolt is not seen, instead one sees the whole cloud light up from inside. Lightning that appears to travel extensively along the cloud anvil or its base is commonly called a crawler, or sometimes 'spider lightning'. Discharges of electricity in anvil crawlers travel up the sides of the cumulonimbus cloud branching out at the anvil top.

[Cloud-to-ground lightning, anvil-to-ground lightning]
Cloud to ground lightning strikeCloud-to-ground lightning is a great lightning discharge between a cumulonimbus cloud and the ground initiated by the downward-moving leader stroke. This is the second most common type of lightning, and poses the greatest threat to life and property of all known types. One special type of cloud-to-ground lightning is anvil-to-ground lightning, a form of positive lightning, since it emanates from the anvil top of a cumulonimbus cloud where the ice crystals are positively charged. In anvil-to-ground lightning, the leader stroke issues forth in a nearly horizontal direction until it veers toward the ground. These usually occur miles ahead of the main storm and will strike without warning on a sunny day. They are signs of an approaching storm and are known colloquially as "bolts out of the blue".

[Cloud-to-cloud lightning]
Cloud-to-cloud or inter cloud lightning is a somewhat rare type of discharge lightning between two or more completely separate cumulonimbus clouds.

[Ground-to-cloud lightning]
Ground-to-cloud lightning is a lightning discharge between the ground and a cumulonimbus cloud from an upward-moving leader stroke. These thunderstorm clouds are formed wherever there is enough upward motion, instability in the vertical, and moisture to produce a deep cloud that reaches up to levels somewhat colder than freezing. These conditions are most often met in summer. Lightning occurs less frequently in the winter because there is not as much instability and moisture in the atmosphere as there is in the summer. These two ingredients work together to make convective storms that can produce lightning. Without instability and moisture, strong thunderstorms are unlikely. Lightning originates around 15,000 to 25,000 feet above sea level when raindrops are carried upward until some of them convert to ice. For reasons that are not widely agreed upon, a cloud-to-ground lightning flash originates in this mixed water and ice region.