English: Transient luminous events (TLEs)

Large thunderstorms are capable of producing other kinds of electrical phenomena called transient luminous events. The most common TLEs include red sprites, blue jets, and elves.

Red sprites can appear directly above an active thunderstorm as a large but weak flash. They usually happen at the same time as powerful positive CG (cloud–ground) lightning strokes. They can extend up to 60 miles (96 km) from the cloud top. Sprites are mostly red and usually last no more than a few seconds, and their shapes are described as resembling jellyfish, carrots, or columns. Because sprites are not very bright, they can only be seen at night. They are rarely seen with the human eye, so they are most often imaged with highly sensitive cameras.

Blue jets emerge from the top of the thundercloud, but are not directly associated with cloud-to-ground lighting. They extend up in narrow cones fanning out and disappearing at heights of 25–35 miles (40–56 km). Blue jets last a fraction of a second and have been witnessed by pilots.

Elves are rapidly expanding disk-shaped regions of glowing that can be up to 300 miles (480 km) across. They last less than a thousandth of a second, and occur above areas of active cloud to ground lightning. Scientists believe elves result when an energetic electromagnetic pulse extends up into the ionosphere. Elves were discovered in 1992 by a low-light video camera on the Space Shuttle.