Bolts from the blue

Skyseeker/Flickr

Skyseeker/Flickr

Getting struck by lightning is something we think will never happen to us, but that kind of thinking can get you killed.

There have been 13 fatalities from lightning strikes in the United State this year, according to the National Weather Service. None were in New Jersey, but between 2006 and 2012, the service blamed lightning for the deaths of 13 state residents. About 400 Americans are struck annually. Only 20 percent die outright but another 25 percent suffer disabilities that affect them for the rest of their lives.  

At any given moment, scientists estimate there are some 2,000 thunderstorms boiling above the globe, discharging 100 lighting strikes per second. The average bolt packs a walloping 200 million volts, more than enough for a direct hit to kill instantly. But a direct strike isn’t the only danger.

True to the imperative — finding the path of least resistance — these giant sparks of static electricity can strike you after bouncing off metal fences, trees, party tents and flagpoles, or while traveling up to 60 feet through the ground from the point of contact.

Current also can travel through wiring, plumbing, air conditioning ductwork and telephone lines. In fact, many of those injured indirectly were talking on landline phones during thunderstorms.

Lightning develops when the electrical charges within a storm cloud are wrenched apart. The process is poorly understood, but scientists believe that rain drops attract a negative charge and, being heavier than air, sink to the bottom of the cloud. Meanwhile, strong updrafts thrust the positive charge to the top of the cloud.

Tall objects are more vulnerable because they lift positive charges higher off the ground and closer to the storm cloud. The old adage that one should not seek shelter in a thunderstorm under isolated tall trees is sound advice on three counts.

For one thing, that towering tree can attract a direct hit. Another danger has to do with the path of least resistance. Water is an excellent electrical conductor, and while the tree has a moisture content of 20 percent,  yours is 65 percent. Can you guess where the charge is headed? Finally, even if you avoid getting hit directly or on the bounce, an impacted tree can shatter, catch fire or fall.

Tree shattered by lightning                Timo Newton Syms/Flickr

Tree shattered by lightning                Timo Newton Syms/Flickr

Weirdly, lightning can strike as much as 10 miles from the place where a storm is dumping rain, and can come quite literally as a bolt out of the blue. A 22-year-old East Windsor man was killed on the beach at Island Beach State Park in 2001 in hazy sunshine on a hot July day. There was no thunder heard, no warning at all.

This incident aside, you rarely get fury without sound. Thunder is a byproduct of the shock wave produced by the passage of those super-heated electrical discharges we call lightning. And sound, traveling one-fifth of a mile per second, always follows light, which is zipping along briskly at 186,000 miles per second.

I always believed that the seconds between the flash and the bang equaled the number of miles between you and the storm. Not so. You must count the seconds and divide by five. A 10-second interval means the storm is not 10 miles away, but two, and a lot closer than you thought.

The worst place to be in a thunderstorm is in the open, as on sports fields, bare mountain tops, beaches or farmland. Contrary to what many think, only five percent of injuries occur on the golf course; 27 percent took place in open areas, 14 percent under trees and eight percent on or near water, another hazardous location.

The safest place to be is in an enclosed building with plumbing and wiring to conduct the charge to the ground — pavilions, dugouts and tents don’t count. A hardtop car with the windows rolled up is a good second choice, but avoid contact with metal parts. Forget the convertible, and step away from metal bikes or motorcycles.

Let’s say you are caught out with no shelter, not even a ditch or depression to lower yourself into. If the hair on your arms rises or you hear crackling noises preceding a lighting strike, you are in imminent danger. Adopt the pose: Put your feet together, crouch down as low as possible, cover your ears to protect against rupture and close your eyes. Move to a better location as soon as possible.

An ounce of prevention is ever worth a pound of cure. Be aware of the forecast if you plan to be outdoors, and follow the 30/30 rule: Seek appropriate shelter if the interval between lightning and thunder is less than 30 seconds, and wait for 30 minutes after the last rumble before heading back outside.

According to a National Geographic article, your chances of getting hit by lightning in any given year are 1 in 700,000; if you live to be 80, your odds rise to 1 in 3,000 over your lifetime. Those aren't awful odds --  but hey,  why push it? Better safe than sorry.