Lightning strikes kill about 58 people in the U.S. each year, making it one of the top weather killers despite being underrated. Lightning results from a buildup of positive and negative charges within a thunderstorm cloud and between the cloud and ground. When the charge difference becomes large enough, a conductive path forms from the cloud to the ground through which current surges, creating a visible lightning flash. The safest place during a thunderstorm is inside a substantial structure without plumbing or electronics.

1. National Oceanic and Atmospheric Administration
U.S. Department of Commerce
NOAA Knows...
Lightning
L
ightning is one of the most underrated severe they carry. The soft
weather hazards, yet ranks as one of the top hail causes a negative
weather killers in the United States. Lightning charge build up near
strikes in America kill about 58 people and injure the middle and lower
hundreds of others each year. part of the storm
cloud which, in turn,
Unlike other weather hazards that often involve
causes a positive
sophisticated watches and warnings from NOAA’s
charge to build up on
National Weather Service, lightning can occur anywhere
the ground beneath
there is a thunderstorm. That’s why the National Weather
the storm cloud.
Service conducts an on-going campaign to educate
people about lightning risks. Eventually, when the charge difference between the
negative charge in the cloud and the positive charge on
The Shocking Truth the ground become large, the negative charge starts
Lightning is a rapid discharge of electrical energy in moving toward the ground. As it moves, it creates a
the atmosphere. The resulting clap of thunder is the result conductive path toward the ground.
of a shock wave created by the rapid heating and cooling
This path follows a zigzag shape as the negative
of the air in the lightning channel.
charge jumps through segments in the air. When the
During a thunderstorm, negative charge from the
winds within the thunder- cloud makes a connection
storm cloud cause collision
Lightning Quick Facts with the positive charge on
between the various the ground, current surges
4 Lightning often strikes the same place
precipitation particles within through the jagged path,
the storm cloud. These repeatedly if it is a tall, isolated object. creating a visible flash of
collisions cause very small 4 Most lightning victims are in open areas
lightning.
ice crystals to lose electrons or near a tree. Thunder, high winds,
while larger particles of soft
darkening skies, rainfall
hail gain electrons. 4 In Florida, lightning kills more people
and brilliant flashes of light
Upward winds within than all other storm-related are warning signs for
the cloud redistribute these weather events. lightning strikes.
particles and the charges 4 Lightning can heat its path through the air
to five times hotter than the surface of (continued on back)
the sun.

2. While most lightning casualties occur at the Thunder becoming louder or
beginning of an approaching storm, a significant number more frequent is a sign that
of lightning deaths occur after the thunderstorm has lightning activity is approaching,
passed. If thunder is heard, then the storm is close enough increasing the risk for lightning
for a lightning strike. It is very important to seek safe injury or death.
shelter immediately.
Organizers of outdoor events
When Thunder Roars, Go Indoors should monitor the weather and
evacuate participants as soon as
The safest place to be when lighting threatens is
they hear thunder. School buses are
in a substantial structure with electricity and plumbing.
excellent lightning shelters.
However, when inside during a thunderstorm, avoid
Consider placing lightning
contact with anything that could conduct a lightning
safety tips and/or the action plan in game programs,
strike to you, including anything that plugs into a wall
flyers, scorecards, etc., and placing lightning safety cards
outlet, corded phones, plumbing, metal doors, and
around the area.
window frames.
Most importantly, keep an eye on the sky, listen for
This means do not take a shower or bath during a
thunder, and stay informed by listening to NOAA
thunder storm. Battery-operated computers and cell
Weather Radio–All Hazards.
phones are fine. Generally, enclosed metal vehicles (not
convertibles), with the windows rolled up, provide good For more lightning information and safety tips, visit
shelter from lightning. http://www.lightningsafety.noaa.gov.
If a storm is To learn more about NOAA, visit http://www.noaa.gov.
approaching, get
inside immediately.
Gazebos, rain or
picnic shelters,
baseball dugouts,
convertible vehicles,
and golf carts do not
provide protection
Cattle killed by a single lightning strike. from lightning.
When lightning can be seen or heard, the danger is
already present.
December 2009