Does lightning go up or down? There are two ways that flashes can strike ground: naturally downward those that occur because of normal electrification in the environment , and artificially initiated or triggered upward.
Artificially initiated lightning is associated with things like very tall structures, rockets and towers. Lightning can also be triggered by aircraft flying through strong electric fields. If the plane is below the cloud, then a CG flash could result.
In the most common type of cloud-to-ground lightning CG , a channel of negative charge, called a stepped leader, will zigzag downward in roughly yard segments in a forked pattern. This stepped leader is invisible to the human eye, and shoots to the ground in less time than it takes to blink. As it nears the ground, the negatively charged stepped leader causes streamer channels of positive charge to reach upward, normally from taller objects in the area, such as a tree, house, or telephone pole.
When the oppositely-charged leader and streamer connect, a powerful electrical current begins flowing. This return stroke current of bright luminosity travels about 60, miles per second back towards the cloud. A negative CG flash consists of one or perhaps as many as 20 return strokes.
We see lightning flicker when the process rapidly repeats itself several times along the same path. The actual diameter of the lightning channel current is one to two inches, surrounded by a region of charged particles. The more common cloud-to-ground flash has a negative stepped leader that travels downward through the cloud, followed by an upward traveling return stroke.
The net effect of this flash is to lower negative charge from the cloud to the ground so it is commonly referred to as a negative CG or -CG. Storms which produce mostly negative CGs tend to produce CGs earlier in the storm lifecycle and produce significantly more CGs than similar storms which instead produce mostly positive CGs.
The greater the distance between contact points, the greater the potential for death or serious injury. Because large farm animals have a relatively large body-span, ground current from a nearby lightning strike is often fatal to livestock. Lightning can travel long distances in wires or other metal surfaces. Metal does not attract lightning, but it provides a path for the lightning to follow.
Most indoor lightning casualties and some outdoor casualties are due to conduction. Whether inside or outside, anyone in contact with anything connected to metal wires, plumbing, or metal surfaces that extend outside is at risk. This includes anything that plugs into an electrical outlet, water faucets and showers, corded phones, and windows and doors. Streamers develop as the downward-moving leader approaches the ground. Typically, only one of the streamers makes contact with the leader as it approaches the ground and provides the path for the bright return stroke; however, when the main channel discharges, so do all the other streamers in the area.
If a person is part of one of these streamers, they could be killed or injured during the streamer discharge even though the lightning channel was not completed between the cloud and the upward streamer.
Please Contact Us. Luckily, the jolt of lightning did not seriously injure the instructor. She was able to get up and enter the building. Later, a nearby hospital treated her for minor injuries. This swim instructor got lucky. Sometimes, indirect lightning strikes are dangerous or even deadly. Six guests at the PGA Championship Tour learned that the hard way when lightning struck a nearby tree.
Luckily, all six victims survived. Does your organization worry about protecting visitors, employees, or infrastructure from lightning strikes? How do you know which system is the best one to safeguard what matters to you most from severe weather?
Download our Outdoor Alerting System Buying Guide to find out all the features you should look for when you decide that lightning is a priority at your organization. Earth Networks offers a variety of weather safety.
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