They are quite beautiful as they streak across the sky, but when they aim their tremendous power downward beware because they can seriously injure or even kill you. I’m talking about lightning bolts. This is the season when thunderstorms are most likely to build up in the Pacific Northwest and we should all be aware of the measures needed to keep us from being struck by lightning. I discussed this subject back in 2013, but I think it is time to review what we all need to know.
A bolt of lightning can be as hot as 54,000 degrees F. with an average peak current of 30,000 amperes, and produces 500 megajoules (MJ) of energy (138.889 kilowatt hours). To give another comparison, the “average nuclear reactors used for power generation are rated at 500-1000 MJ each, so they put out 500 to 1,000 MJ every second.” That’s according to the contributor to Yahoo! answers.
Lightning is usually formed in a cumulonimbus cloud or thunderhead. It is the result of a build-up of electrical charges within the cloud. The upper part of the cloud which reaches into the colder part of the atmosphere forms ice crystals that are usually positively charged. Raindrops form in the lower portion of the cloud and they contain a negative charge.
As the cloud moves over the land the negative charge at the bottom of the cloud induces a positive charge at or near the surface. As you’ve heard many times before opposites attract and an electrical charge builds between the bottom of the cloud and the surface or something standing on the surface like a building, tower, or even a person standing outside. A leader comes down from the cloud toward whatever it is attracted to and an upward streamer moves from the object up to the cloud. When they meet the path to the ground is completed. A return stroke then follows the path back up to the cloud at an incredible speed of 60,000 miles per second. That’s what forms the bright flash. The flash is actually moving from the object upward even though your eye sees it as striking down from the cloud.
The noise of the thunder comes from the rapid heating and cooling of the air (expansion and contraction) around the lightning bolt.Lightning displays can be beautiful, especially at night, but they can also be deadly.
We should be thankful that there are four major categories of lightning: within-a-cloud, cloud-to-cloud, cloud-to-air, and cloud-to-ground. If all we had were cloud to ground lightning strikes people all over the world would be constantly ducking and weaving to keep away from the deadly electrical charges.
Many people have studied lightning, but Benjamin Franklin is probably the best known. His key on a kite string experiment was performed to prove that lightning was naturally occurring electricity. He did get shocked during one of his experiments and I have heard that some scientists say Franklin was very lucky he didn’t get electrocuted flying his kite with the key on the string. Franklin also invented the lightning rod.
Others who have tried to duplicate Franklin’s experiment have reportedly been electrocuted and I have heard they died trying. I know of a true story that happened in the Midwest. A farm worker loved flying kites, but he got tired of constantly having to replace kites lost when the string broke in the wind. So, “Mr. genius” decided to use a large spool of industrial strength copper wire figuring it was much stronger than string and he would never lose a kite again. Well, he used his copper wire and ran it out so the kite was so high he could hardly see it. I’m sure you already figured out what comes next. Lightning struck his kite, followed the copper wire down to his hands, and instantly electrocuted him. His death reminds me of my favorite quote from the movie Forrest Gump “Stupid is as stupid does.”
Lets clear up some myths about lightning. Lightning never strikes twice in the same place. Wrong! If the target still stands it can be struck again and quite often is. As long as you stay inside during a thunderstorm you are safe from lightning. Wrong! Lightning has been known to strike people through windows and it can strike a telephone, cable, or power line and follow it into your house through the wire. A neighbor of mine in Memphis, TN, more than twenty five years ago, had the bolt of lightning strike the power line into the house and burned the inside of their dishwasher, fried the toaster, and blew out the microwave oven all of which were connected into the same circuit.
There are other ways to produce lightning. Dust storms and forest fires can produce the elements needed to produce lightning and another example is the eruption of Mt. St. Helens on May 18, 1980. Pyroclastic explosions spew various sizes of material from large boulders to fine particles of dust and ash. Sending hot gasses upwards of 6 miles into the colder part of the troposphere added to the particulates equals a good recipe for lightning above the cone of an active volcano.
Now that we’ve seen the dangers of lightning I think we should discuss what you can do to be more protected from it’s deadly charge. What if you are outside without shelter of any kind? The National Weather Service recommends that you immediately squat down putting your hands over your ears. That way you are a smaller target and if you do get struck the charge would pass through your body more quickly, hopefully doing less damage. Stay away from trees and other tall objects and if you can avoid it don’t stand in puddles or on wet ground.
Is a car a safe place to be in a thunderstorm? If you can’t get to a building a car is a relatively safe place. Don’t touch any metal inside and the metal shell of the car will shield you.
The same goes for being a passenger in an airplane flying in or near a thunderstorm. Most of the strikes to the body of the plane have no effect because the plane has a modified lightning rod, but a strike to one of the engines could do some serious damage. If you are inside a building remember to stay away from windows and stay off the telephone or any electrical equipment as long as the storm is near you.
Can lighting effect more than one person at a time? It certainly can. During a baseball game a thunderstorm built up and lightning struck the pitcher. The lightning continued along the ground and knocked down the entire infield. There is one man who is in the Guinness Book of World Records for being struck 7 times (from 1942 until 1977) and living to tell his story.
Roy Sullivan started working as a park ranger in Shenandoah National Park in Virginia back in 1936. After being struck a number of times people stayed away from him for fear of being struck with him. They began calling him the “Human Lightning Rod.” The last time he was struck he was fishing and just after being struck a bear came up and tried to steal the trout he had on his fishing line, but he had the strength and courage to hit the bear with a tree branch and keep his fish.
Does the storm have to be overhead for you to get struck by lightning? No! “A bolt out of the blue” is a lightning bolt that comes from a storm that is not overhead, but can be 10 or more miles away. If you can hear thunder or see even the glimmer of the lightning in the distance you are at risk for being struck. Stay indoors until the storm is well away from your area. Just in case you were wondering, the odds of being struck by lightning are computed to be 1 in 10,000. I’ll bet Roy Sullivan would have some choice words to say about that.
Now that you are armed with all of this information you need to remember it when the next thunderstorm approaches.You might remember the little trick to determine the approximate location of the lightning strike. Count the number of seconds between the flash and the thunder and divide by five. That will give you an estimate of how many miles away the strike was from your location. That works because the speed of light is about 5 times faster than the speed of sound.You may have heard of “Heat Lightning” that occurs in hot weather Summer thunderstorms. Technically it doesn’t exist. The storm is far away enough that you can see the lightning flash, but too far away for the sound waves to reach you.
Let me know what you would like me to talk about or explain. You can comment below or email me at: firstname.lastname@example.org.