Each year, nearly 100 people are killed by lightning, more than hurricanes and tornadoes combined. And with temperatures approaching 50,000 F, it's easy to see why lightning is one of the most dangerous of weather phenomena. Lightning occurs when electricity flows between two objects of opposing electric charge.
Lightning can occur within a cloud, between clouds, and from a cloud to the ground.
The lightning bolts that concern us most are those that travel from clouds to the ground because they can kill people and start fires. Anatomy of a Lightning Stroke Negatively charged electrons begin zigzagging towards the ground in a forked pattern. This invisible discharge is called the stepped leader . As the stepped leader heads towards the ground, it attracts positively charged protons upward, usually in tall objects, such as trees. The protons in the object begin to form a traveling spark upward towards the stepped leader.