In describing lightning, what is a “stepped leader?
” A: A stepped leader, a bundle of negative charge that is the first step in a typical lightning strike, moves from cloud to ground in fits and stars. Each step is about 50 yards long, with a duration of less than one-millionth of a second. The leader pauses about 50 microseconds before taking the next step, possibly branching a number of times during this stepping process. Most stepped leaders take only 1/20th of a second to reach their full length. As a stepped leader nears the ground, it attracts a surge of positive charge that streams skyward from the tallest nearby objects. The stepped leader and “streamers” typically meet around 100 to 300 feet above the Earth. This National Weather Service webpage has a great explanation of stepped leader and the entire process behind lightning strikes.
