Avoiding the Risks
of Deadly Lightning Strikes
Lightning is one of the most
underrated severe weather hazards, yet ranks as the second-leading
weather killer in the United States. More deadly than hurricanes
or tornadoes, lightning strikes in America each year kill an
average of 73 people and injure 300 others, according to NOAA's National Weather Service.
How Lightning Works
Lightning is caused by the attraction between positive and negative
charges in the atmosphere, resulting in the buildup and discharge
of electrical energy. This rapid heating and cooling of the air
produces the shock wave that results in thunder. During a storm,
raindrops can acquire extra electrons, which are negatively charged.
These surplus electrons seek out a positive charge from the ground.
As they flow from the clouds, they knock other electrons free,
creating a conductive path. This path follows a zigzag shape
that jumps between randomly distributed clumps of charged particles
in the air. When the two charges connect, current surges through
that jagged path, creating the lightning bolt.
The Warning Signs
High winds, rainfall, and a darkening cloud cover are the warning
signs for possible cloud-to-ground lightning strikes. While many
lightning casualties happen at the beginning of an approaching
storm, more than 50 percent of lightning deaths occur after the
thunderstorm has passed. The lightning threat diminishes after
the last sound of thunder, but may persist for more than 30 minutes.
When thunderstorms are in the area, but not overhead, the lightning
threat can exist when skies are clear.
While nothing offers absolute safety from lightning, some actions
can greatly reduce your risks. If a storm is approaching, avoid
being in, or near, high places, open fields, isolated trees,
unprotected gazebos, rain or picnic shelters, baseball dugouts,
communications towers, flagpoles, light poles, bleachers (metal
or wood), metal fences, convertibles, golf carts and water. If
you can see lightning or hear thunder, the risk is already present.
Louder or more frequent thunder means lightning activity is approaching,
increasing the risk for lightning injury or death. If the time
delay between seeing the lightning and hearing the thunder is
less than 30 seconds, you are in danger.
No place is absolutely safe from
the lightning threat, however, some places are safer than others.
Large enclosed structures are safer than smaller, or open, structures.
Avoiding lightning injury inside a building depends on whether
the structure incorporates lightning protection and its size.
When inside during a thunderstorm, avoid using the telephone,
taking a shower, washing your hands, doing dishes, or having
contact with conductive surfaces, including metal doors, window
frames, wiring and plumbing. Generally, enclosed metal vehicles,
with the windows rolled up, provide good shelter from lightning.
Action Plan For Outside Events
Coordinators of outdoor events should monitor the weather and
evacuate participants when appropriate. School buses are an excellent
lightning shelter, which outdoor event organizers can provide.
Consider placing lightning safety tips and/or the action plan
in game programs, flyers, scorecards, etc., and placing lightning
safety placards around the area. Lightning warning signs are
effective means of communicating the lightning threat to the
general public and raise awareness.
First Aid for Lightning Victims
Ninety percent of lightning victims survive their encounter with
lightning, especially with timely medical treatment. Individuals
struck by lightning do not carry a charge, and it is safe to
touch them and provide medical treatment. Call 911 and start
mouth-to-mouth resuscitation. If the victim has no pulse, begin
cardiac compressions. In cold, wet situations put a protective
layer between the victim and the ground to lower the risk of
Lightning Quick Facts
- 25 million cloud-to-ground lightning
strikes occur in the United States each year
- The air within a lightning strike
can reach 50,000 degrees Fahrenheit
- Lightning can heat its path
five times hotter than the surface of the sun
- One ground lightning stroke
can generate between 100 million and 1 billion volts of electricity
For more information contact
National Weather Service
public affairs at (301) 713-0622 or visit NOAA's
Lightning Safety Web Site.
| Reporter Resources | NOAA
Updated June 2001