Lightning Storms
What Is Lightning?
Lightning Protective Devices
Lightning Safety Rules
What Is Lightning?
All thunderstorms produce lightning. It is a surprising fact to most
people that, on average, lightning kills more people across the United
States each year than tornadoes. Lightning accounts for an average
of 93 deaths annually, second only to flooding in weather related deaths.
Since lightning casualties usually occur only one or two at a time,
this killer does not get the national attention it deserves.
Lightning is also one of the most intense and powerful phenomena
associated with thunderstorms. It develops as a result of interactions
between charged particles in the atmosphere, which produce an intense
electrical field within and near the thunderstorm. Electrical potential
in lightning can reach 100 million volts. Lightning strokes usually
occur from cloud to cloud or cloud to ground. However, they can also
originate from high surface locations and move up into the thunderstorm
cloud.
Lightning Protective Devices
Several devices exist to protect structures and electrical equipment
from potential damage caused by a direct lightning strike. A lightning
rod is a grounded metal rod placed high on a structure to prevent damage
by conducting lightning directly to the ground. A lightning arrester
is a protective device for electrical equipment that reduces excessive
voltage resulting from lightning to a safe level by grounding the discharge.
Lightning Safety Rules
Sometimes lightning can be deadly, with frequent cloud to ground
strikes. When thunderstorms are near, get inside a building or vehicle
that is fully enclosed. Do not stand near isolated tall objects. Lightning
usually seeks the shortest path from the thunderstorm to the surface
below.
If you are in a home or building, avoid using a corded telephone,
except for emergencies. Cordless telephone systems are safer if you
must use the phone. Stay away from open windows or doors, fireplaces
and chimneys, and radiators and metal pipes. Avoid plugged-in electrical
appliances. When lightning strikes a building, it frequently travels
through plumbing, electrical systems and chimneys.
If you are caught outside, stay away from fence posts, utility poles
and tall trees. Stay off tractors, golf carts, motorcycles and bicycles.
Get off athletic fields and stay away from the backstops and fences
around baseball and softball diamonds. Do not use metal objects such
as golf clubs or fishing rods. Get out of and away from open water.
Do not seek shelter from thunderstorm rains under an isolated tree
or in a small, isolated shed or picnic shelter in an open area. Avoid
projecting above the surrounding landscape by moving to lower ground,
but avoid creek beds and storm drains that could flood.
If there is no shelter available and you feel an electrical charge
making your hair stand on end or your skin tingle, immediately crouch
down low to the ground, with your weight resting on the balls of your
feet. Do not lie flat.
If you see a group of people struck by lightning, administer CPR
first to those who appear to be dead. Quick action can often restore
a heartbeat and breathing. Remember that lightning frequently strikes
several miles away from the thunderstorm, so take precautions even
when the storm is not directly above you.
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