Upwards Lightning

The lightning strike is the phenomenon that occurs when a thunder cloud is connected via rising and falling tracers to the ground. It occurs after two tracers have joined. All the charge contained in the thunder cloud rushes into the ionized channel formed by the two tracers and produces an electric discharge.

 The lightning in the photograph above hit one of two tracers rising from the tree. A third ionized channel 'tracer' is visible to the left of the tree, rising from a telegraph pole.