About 70 percent of lightning fatalities occur in June, July and August.
The simplest explanation is that in electrically charged storm systems, such as thunderstorms, ice particles are constantly colliding at the boundary between the darkest clouds (the anvil) and the lighter ones.
The collisions create huge electrical fields that, when the difference in charge between the upper and lower portions of the cloud is wide enough, can release a bolt of electricity.
What we see as a single flash is really a series of strokes. The bolt is the size of a quarter or half-dollar, hotter than the sun’s surface and generally 4 to 6 miles long. The heat expands almost instantaneously, causing thunder.
Lightning can strike the same place twice, especially on mountaintops, so hikers and climbers beware. It has a good side aside. Lightning creates nitrogen oxide that generates a large percentage of usable nitrogen in the air and soil. And lightning-caused forest fires can create space for new growth.
ANTI-LIGHTNING TACTICS
Forget the flash-to-bang rule. Still popular, the flash-to-bang estimate more or less tells you how far away you are from lightning (sound travels about one mile in five seconds). But many factors contribute to when you can hear the sound, if you can, and there’s no way of knowing how far away a particular bolt will strike.
Find refuge, but. Being inside a home (or a car, in a pinch) is much safer than being outside. But because homes are often struck by lighting, avoid a bath or shower during a lightning storm, don’t use a landline phone, TV or other appliances that conduct electricity, and put off washing the dishes. Talking on a landline phone is the leading cause of lightning injuries inside the home.
No place to hide? If you’re caught outside in a lightning storm, seeking shelter under a tall tree or being on the water are definitely discouraged. Swimming is particularly dangerous because water conducts electricity.
And don’t be the tallest object around. Find a low spot and crouch down but, as much as it might seem sensible, don’t lay down. Lightning that strikes the ground means that its current may move along the surface, where your whole body will be exposed.
If you’re hiking with a group, spread out, which can help prevent multiple injuries and insure that someone can help if there’s an injury.
BY THE NUMBERS
• About 450 people are struck by lightning each year in the United States.
• The odds of becoming a lightning victim is 1 in 700,000 in any one year; of being struck in your lifetime, 1 in 3,000.
• Lightning caused the death or cardiac arrest of 3,700 people in the U.S. between 1959 and 2003. Of those who died, 85 percent were men.
• About 70 percent of lightning-strike survivors suffered long-term damage.
• Each bolt can contain up to one billion volts of electricity
• About 20,000 strokes of lightning from clouds to ground during about 100,000 U.S. thunderstorms every year, or about one per second.
• The planet might be struck by an average of more than 100 lightning bolts every second.
• Lightning causes about 80 percent of all accidental livestock deaths.
Lightning bolts can travel 25 to 40 miles horizontally before heading to ground. A 110-mile-long bolt was detected traveling from Waco to Fort Worth-Dallas.
The National Oceanic and Atmospheric Administration contributed to this article.
Columnist Sharon Wootton can be reached at 360-468-3964 or www.songandword.com.
