What is lightning?
Lightning refers to one of the several forms of visible electrical discharge produced by thunderstorms. It is essentially a giant spark that jumps between vast pools of positive and negative electrical charge that form inside thunderstomrs The primary forms of lightning discharges are cloud-to-ground (CG), cloud-to-cloud (CC), in-cloud (IC) and cloud-to-air (CA). Rare forms also include ball lightning. Lightning appears very bright because it is - its optical output is equivalent to some 100 million light bulbs going on and off.
How hot is lightning?
Some like it hot…and they should just love lightning. The air in the core of a lightning bolt has been estimated to be heated to as much as 54,000°F (30,000°C). That happens to be about six times hotter than the surface of the sun.
What are the electrical currents within a lightning discharge?
They are highly variable…but high!. The average lightning stroke has a peak current on the order of 30,000 amps. But some discharges, especially those that are totally within the cloud, are only several thousand amps. On the other hand, superbolts do occur, occasionally reaching 300,000 amps or more. The electrical potentials involved in lightning discharges can range up to 200 million volts.
How often does lightning occur on our planet in a year?
There are probably 1500 to 2000 thunderstorms active around the world at any one time. It has been estimated from satellite observations that lightning flashes approximately 50 -100 times per second on a global basis. Lightning therefore flashes as often as three billion times each year across the whole planet. GO TO TOP
Why does lightning appear to flicker?
When you see a flash of cloud-to-ground lightning, it often appears to flicker. If you were to video tape that flash, on slow play back you would find that many flashes are composed of a succession of multiple strokes, which most of the time follow the exact same path as the initial stroke. Thus flashes are composed of strokes, typically several in number. The actual stroke lasts on the order of millionths of a second, separated in time by several tens of millisecond (thousands of a second). The entire flash can sometimes last for a second or more.
Does lightning strike up or down?
Well, it goes both ways. After the initial lightning leader of a cloud-to-ground event starts within the cloud above, it approaches the ground. As it does, an upward streamer emerges from the object about to be struck. When the two meet, this completes the path to ground, and the cloud is short-circuited with a brilliant, luminous 60,000 mile per second return stroke from the earth back up into the cloud. If the flash has more than one stroke, a dart leader emerges from the cloud and follows the same path (usually) to ground without branching, and as it approaches the object to be hit, another upward streamer emerges, resulting in the next return stroke. Occasionally the stepped leader originates at the ground (more likely from a tall building or tower), and moves upwards. The branching of the first stroke would then look like an upside down tree. This could also be considered true “upside down lightning.”
How many kinds of cloud-to-ground flashes are there?
There are basically two distinct types of CG flashes, as they are often called, negative CGs and positive CGs, though they generally look the same to the naked eye. The negative CG is by far the most common (perhaps 90-95% of the total) and lowers negative charge to the ground. The less common, positive CG lowers positive electrical charge to the ground. The positive CGs typically have stronger peak currents, are less likely to have multiple strokes in a flash, and often have a continuing current which, lasting many tens of milliseconds, allows the struck object to be intensely heated and causing ignition. The positive CGs are thought to be the chief forest fire starters. They also seem to be the cause of sprites. GO TO TOP
What is thunder?
The angels bowling? No. Thunder is the sound emitted as a result of the rapidly expanding gases along the heated lightning channel. When lightning strikes very close by, one sometimes hears a tearing sound. This is believed to be produced by the stepped leader which precedes the first stroke in a flash. The sharp crack heard at very close range, just prior to the main thunder crash, is caused by a ground streamer ascending to meet the stepped leader of the first stroke. A combination of an elve and a sprite above a New Mexico Storm. Courtesy of Dr. Mark Stanley © New Mexico Tech
How far away was the last lightning bolt?
How close was that lightning bolt you just saw hit the ground? Count the seconds between the flash and the bang, and divide by 5, and you have the answer in miles. Sound travels at about a mile in five seconds, so by timing the interval between seeing the lightning and hearing the thunder is a pretty good indicator of how close you were to the strike point. If the flash-to-bang time is 30 seconds or less, the last strike was within 5 miles. And statistically in many storms, the following strike usually strikes about to 3 to 5 miles from the last…meaning you could be next!
How often does lightning strike the ground in the U.S. each year?
Lightning detection networks suggest that bolts blast the ground some 25 to 30 million times per year. The lightning hot spot of the U.S. is central Florida. Disneyworld could be called Lightning World. In a typical year each square mile of central Florida is struck some ten times. Most parts of the country east of the Rockies have 10 to 50% of that lightning frequency. GO TO TOP
How wide is a bolt of lightning?
A big lightning bolt striking the ground might seem be hundreds of feet across, but in actuality the current channel is generally not much thicker than a pencil.
How far away from the lightning bolt can you hear the thunder?
Generally thunder can not be heard much more than ten miles from its source. In a city, where ambient noise levels are high, often thunder is audible only when the lightning strikes a mile or two away.
Can lightning come from ice?
As strange as that sounds, lightning, with a temperature hotter than the surface of the sun, only forms in clouds with large quantities of ice. Electric charge is generated during freezing and melting processes in the presence of snow and supercooled water droplets.
Does Florida always have the most lightning?
During the summer of 1993, not only were torrential rains pelting the Midwest (resulting in great floods), but for the first time since automated lightning detection networks began, the national lightning "hot spot" was located in Missouri-not Florida. GO TO TOP
Thunderstorm approaching. Where to go?
A car or truck (with windows closed) or the inside of a building are your best bets. Where not to go? Avoid standing under trees, near fences, railroad tracks, tents, hilltops, golf carts, or holding onto telephones, electrical appliances or plumbing. And stay out of the water! Open sided rain shelters are not particularly good protection from lightning, either.
Can you have thunder without lightning?
Can’t be done, if only by definition. But you might not always be able to see the parent lightning discharge. Especially during the daytime, lightning discharges deep within a cloud are difficult to see. And more than 80% of all lightning discharges remain inside clouds. GO TO TOP
Can you survive a lightning strike?
Yes, in fact the majority of the people struck do not die. Estimates of the mortality rate from lightning strikes range from 5% to 30%. But your odds of survival are significantly enhanced if you are struck in the presence of someone who knows CPR. The basic rule to follow if several people are struck by lightning is to “treat the dead first.” Often lightning victims appear dead but are in fact in cardiac arrest. The immediate application of CPR can bring them back to “life.” More often than not people who have been struck and are screaming and howling, while obviously in pain, are usually in less imminent medical danger. Many people think that someone who has been struck by lightning are still somehow electrically charged. This is nonsense. There is no danger whatsoever in touching a lightning strike victim.
More people are killed by lightning every year than by rattlesnake bites. You have less than 3 chances in a 100 of actually dying from a rattler bite. If you have the choice between the reptile and the big spark, go with the snake.
Can you survive a lightning strike more than once?
Some people like to push the odds. And at least one person has been hit by lightning some seven times and survived. An American park ranger by the name of Roy Sullivan was nailed seven times between 1942 and 1977. Known as the "human lightning rod", Mr. Sullivan survived being struck although his hair was set on fire twice and he suffered burns on various parts of his body. But he lived. Kids, he was a professional. Don't try that at home. While being struck by lightning does not mean automatic death, especially who knows CPR is nearby, who wants to take that kind of chance?
Do lightning strike victims burst into flames?
In spite of the Saturday morning cartoon depictions, those struck by lightning do not become crispy critters. Some of their clothing may be singed and smoking and they may have burn marks. But flames? No. GO TO TOP
What is a fulgerite?
OK, you're digging out in the back yard garden. You strike something hard. You keep digging...and unearth a 15 foot long, hard lumpy tubular "thing" that is white/green/gray in color. Quiz: What have you found? (1) Part of a UFO (2) A giant dinosaur leg bone? (3) fossilized lightning. Number 3 is the winner. Called a "fulgerite" it forms when a powerful lightning bolt melts the soil into a glass-like state. Such a record large specimen was found several years ago in Michigan.
Visitors to the Great Sand Dunes National Park in Colorado get to see examples of fulgerites extracted from the nearby sand mountains. And in order to make a point to the many hikers who take off for a long stroll through the dunes, the last sign they see warns them to take cover in thunderstorms and “ not to become fulgerites.”
How safe are you from lightning inside an airplane?
Commercial airliners are generally quite safe during electrical storms. A commercial airliner is on the average struck by lightning twice per year. Not to worry-the metal skin of the plane conducts the current on the outside like a Faraday cage. Fuel tanks are now designed to prevent entry of electrical charges. GO TO TOP
The last major U.S. commercial airliner crash caused by lightning was more than 35 years ago and was the worst lightning related aviation disaster. It occurred over Elkton, MD on 8 December 1963. Lightning struck and penetrated the reserve fuel tank, igniting the vapors and sending the plane in a fiery crash, killing 82 persons. This tragedy resulted in numerous design changes in aircraft to prevent its repetition.
Flying through a thunderstorm can be a bouncy and sometimes unnerving experience. But while the up- and downdrafts can be a potential hazard, you at least don't have to worry much about lightning. If struck by a bolt, the current is largely directed around the outside of the aircraft's metallic skin. Passengers might see a flash, hear a bang, but as for a shock, or worse, not to worry.
Since today’s commercial airliners are well protected from lightning strikes, a direct strike usually causes little or no problems. Usually. On August 4, 1992, a DC 10 flying from Denver to Minneapolis flew into a thunderstorm. It took a direct hit. In addition to burned out electronics, some of the rivets on the fuselage were damaged.
How safe are you from lightning inside your car?
You are generally safe from lightning while inside a car. The rubber tires may provide some shielding, but it is the metal body which provides a safe path for the current to flow to ground on the outside of the vehicle that provides the protection. GO TO TOP
Being struck in a vehicle can be an experience though. Lightning struck and severely damaged a pickup truck in Blue Earth County, Minnesota on 7 August 1994. The occupants inside? No problem. A car traveling on I-35 near Des Moines, IA was struck directly by a bolt of lightning. The car stopped dead in its tracks, but the startled driver was none the worse for wear. The car had major electrical damage, many small holes in its body, and all four tires eventually went flat. The roadway beneath the car had a yard wide, several inch deep crater. The driver’s first name was Rod and the most enduring effect of the incident is that his friends now insist in calling him Lightning Rod
It was just one of those days. Two Michigan motorists had an accident during a rainstorm. While huddling under an umbrella watching the tow truck hoist their wrecked car, lightning struck the umbrella, zapped the motorists, and then jumped over and shocked the tow truck driver. None were seriously hurt, but they were not in a good mood by day's end.
We note that a car can be very dangerous place to be during a tornado. Standing under a tree is a also bad idea during both a tornado and a lightning storm.
How safe are you from lightning inside your home?
Being inside a building during a lightning storm is generally quite safe. Of course you don’t want to be talking on the phone (cordless or cellular excepted), holding on to plumbing fixtures, or working with electrical appliances. GO TO TOP
And there are some exceptions. A lightning bolt struck a house in Denmark, went down the chimney, knocking plaster off the living room walls, ripping curtains to shreds, and smashing a clock to bits...while leaving a caged canary inches away unfazed....then breaking 60 window panes and all mirrors, blasting through the door into the back yard, killing a cat and a pig before burrowing into the ground. Lightning can do weird things. A house in Iowa was severely damaged by a lightning bolt. A pile of twelve dinner plates was found to have every other one broken.
On 24 October 1991, one resident of Chicago Heights, IL was comfortably sleeping in bed when....KABOOM. Lightning struck, traveled through a cable television line into the house, struck the bed, which then caught fire. The person was treated for shock (not the electrical kind).
Was this dumb luck or divine intervention?
A 75 year old German grandmother was being attacked by a street burglar. As the assailant raised a crowbar with which to strike her, he in turn was struck dead by a bolt of lightning. The woman notes her attendance at Church has become more frequent since the incident. We will let the reader decide for his or herself the theological implications of the incident. GO TO TOP
Is lightning a sign from a Higher Power?
We’ll continue to avoid theological discourse, but we do note that many cultures have believed this. Ancient Romans saw Jove’s thunderbolts as a sign of condemnation and denied burial rites to those killed by lightning. Some cultures have made medicines from stones struck by lightning. Roman, Hindu and Mayan cultures all held the belief that mushrooms arise from spots where lightning has hit the ground. In ancient Greek mythology, Zeus was the great bearer of rain, thunder and lightning. Spots struck by lightning were frequently fenced in by Athenians and consecrated to Zeus.
Does lightning ever do any good?
Well, it is very pretty and makes for some really neat pictures. It also fixes the nitrogen in the air which is used by plants. And every once in while it does some good deeds.
According to an article published in Scientific American in 1856, an intense lightning discharge hit the ground in Kensington, N.H. and made a hole about a foot wide and 30 feet deep, forming a well which soon filled with good water.
A Greenwood, SC man (by profession an electrician) survived a direct strike by lightning 28 years ago. But since then he has never felt cold. He can stay outside in sub-freezing temperatures wearing summer clothing for hours without discomfort.
About 500-1000 people per year are injured by lightning, and sometimes (albeit rarely) come out ahead-there are several stories of blind people regaining their sight after a tangle with a bolt. Talk about shock treatments!
It is reported that lightning once struck a house in Minnesota, setting it afire. But this bolt must have had a conscience, as it then leaped across the street, striking a fire alarm box. The power surge resulted in an alarm being sounded, and the fire department responded promptly and put out the house fire.
A woman living in Kansas was once talking on the phone with her husband (who had called to find out if she was OK during a storm) when the line was zapped. She was knocked unconscious, and ever since has been absolutely unable to tolerate any alcoholic beverages.
There is a published claim of improved intelligence on psychological testing after a lightning strike. A woman in southern Illinois believes she become psychic after being zapped. She claims to help police agencies in locating missing persons. GO TO TOP
If a lightning flash takes only a fraction of a second, how come thunder lasts so long?
While we see the flash virtually instantaneously, the beginning and end points might be 5 or more miles separated. Due to the slower speed of sound, it takes differing lengths of time for the shock wave to reach our ears. If the lightning channel was two miles long, and assuming it started directly overhead, it would take at least 10 seconds for the rumbling to stop.
How many people are killed and injured by lightning each year?
When people say the chances are the same as being struck by lightning to describe a low probability event, they had better go check their figures. Over 7000 Americans have been killed by lightning in a recent 34 year period. Your chances of being struck by lightning in the U.S. are about 1 in 250,000 and 400,000 in a given year. You can increase your odds, if you would like, by golfing, swimming, boating and just being outside during a thunderstorm. In the U.S. alone each year, between 75 and 150 people are reported killed by lightning with 5 to 30 times that being injured. And these statistics are thought to be underestimates of lightning casualties. It is possible that many lightning victims’ cause of death is listed as burns or cardiac problems.
The deadliest month for lightning fatalities and injuries in the U.S. is July. The large number of thunderstorms combined with numerous vacation trips and other outdoor activities yields this deadly total.
Can there be lightning during a snowstorm?
Lightning is usually associated with thunderstorms, and therefore is thought to be a spring and summer event. Yet lightning does occur during winter, and even during heavy snowfalls and blizzards. Winter lightning appears to be unusually powerful, associated with loud and long thunderclaps. Sometimes associated snowfalls can reach 3 inches an hour. A man was struck by lightning during a blizzard in Minneapolis during March of 1996. He is still alive...and very puzzled.
Are thunderstorms the only source of lightning?
Lightning is usually associated with thunderstorms. On a few occasions, it has been observed within giant steam and debris clouds from erupting volcanoes. Lightning, and even miniature tornado-like vortices attended the spectacular volcanic birth of the island Surtsey, near Iceland. Giant plumes of smoke from large forest fires also have been known to produce lightning, although these smoke clouds were probably in the process of turning into regular thunderstorms. In the western U.S., most forest fires are started by lightning. Sometimes the heat from the intense fires trigger new thunderstorms ... which in turn can produce more lightning. This is called a feedback loop. GO TO TOP
Can lightning strike twice?
In many ways. As mentioned, in a typical lightning flash, often several strokes hit the same spot in rapid succession. Tall structures and buildings such as the Empire State Building in New York City, the Hancock Building in Chicago and the CN Tower in Toronto are hit many times each year. This fact has actually led to lightning research programs using structures like these. In general any object struck by lightning is generally a better candidate to be struck again than something which hasn’t been zapped.
And then lightning does strike twice...and sometimes with apparent malevolence. On 8 August 1937, three persons were killed by a bolt that struck the Jacob Riis Park beach in New York. On 7 August 1938, almost a year to the day later, lightning again struck the same beach, and again killed 3 bathers. And don’t tell a homeowner in Arvada, CO that lightning doesn’t strike twice. His new house was struck during a summer thunderstorm and sustained considerable damage. Just as they were getting things back in shape six weeks later-shazaam! resulting in $30,000 more in fire damage.
Can you make lightning indoors?
Easy, although on a rather small scale. When the indoor relative humidity is very low, which it often is during winter, static electricity built up on your shoes and clothing can generate notable electrical discharges. It can result in “that annoying static cling” on your dress, and a lot more. In fact, each inch of spark represents a potential difference of 40,000 volts. So a three inch discharge represents a 120,000 volt potential difference. This is why you want to protect your PC from static electricity. Cat fur gives up its electrons easily. So if you need to generate an electrical spark .... just grab that kitty and rub away. And when in Boston, check out the Boston Museum of Science which has a great indoor lightning exhibit featuring a massive Van der Graaf generator. GO TO TOP
Does lightning give off radiation besides light?
In 1895, William Roentgen discovered X-rays. Much more recently atmospheric scientists were surprised to find that thunderstorms can produce X-rays during lightning discharges. Of course lightning also radiates radio energy over a broad range of frequencies. Some of this energy is with the AM broadcast band, which produces the familiar static heard on many summer afternoons and evenings. Another name for this static is sferics, short for atmospherics.
Where does lightning strike?
Lightning strikes most portions of the globe sooner or later, but it does have its favorite haunts. Weather satellites suggest that the vast majority of lightning strikes to the planet occur over land areas, even though it comprises only about a quarter of the earth’s surface. Not too surprisingly, the tropics receive two thirds of the lightning bolts. But some mid-latitude storms, such as those which roam the interior of the U.S. during summer night time hours, can be prodigious producers of lightning. GO TO TOP
What sporting activities are prone to expose you to lightning?
Virtually anything you do outside during spring and summer involves a lightning risk. Swimming, boating, hiking, golfing, soccer...if you are out there, you are a target. Most lightning deaths in the U.S. (in descending order) occur (1) in open fields or ball fields, (2) under trees, (3) while boating and fishing, (4) near tractors and heavy equipment, (5) on golf courses, (6) and on telephones (but not cellular or cordless ones).
A young man fishing in Indiana in 1993 caught more than he was planning on. The fishing rod he carried over his shoulder was struck by lightning as he walked away from a pond. He was hospitalized but did recover. Wonder what his bait was.
Perhaps frisbee is joining golf as a dangerous sport? During a frisbee match in Nashville TN on 10 April 1994, lightning struck. One person was killed and 18 were injured. The safety rules are the same for all outdoor activities. If lightning threatens, get inside-and don’t seek shelter under trees.
Golfers are generally not significantly more often struck by lightning than most outdoors types, but there are plenty of golf-lightning tales. Golfers Lee Trevino and Jerry Heard were both struck by lightning during the 1975 Western Open in Chicago. Both recovered after hospitalization. Over the years, hundreds of other golfers who failed to leave the course after lightning was spotted have been far less fortunate in their encounters. Thor showed his wrath in the land of Vikings in June, 1991. On 13 June one spectator was killed and 5 others injured while taking shelter under a tree during the US Open Gold Tournament near Minneapolis. Then on 29 June, four were injured when lightning struck nearby at a St. Paul golf course.
A 37 year old man was killed by a bolt while golfing near Louisville, KY. Two others were injured. All were standing under a cluster of trees. The rule still stands: don't stand (or sit) under a tree during a thunderstorm. Get inside. GO TO TOP
But with all the talk of lightning hits during recreation, those working for a living in outside jobs are equally at risk. Postal employees, construction workers, farmers, and many others need to take care. Five miners were killed in Texas in May of 1985. They were all taking a lunch break while sitting under a 35 foot oak tree. Only a single lightning flash was seen in a classic “bolt from the blue” scenario.
Cowboys and farmers are at risk. Cowboys are a tough breed. One Utah cowboy was literally blown out of his saddle when struck by a lightning bolt in August 1993. He found a hole in his felt hat, his hair was melted in several spots and he had numerous burn marks on his torso. His faithful steed, however, didn’t survive.
Not everything that happens in an amusement park is funny. Four workers were injured after being struck by a bolt of lightning while they were dismantling a ride in Warrick County, Indiana on 2 September 1991. GO TO TOP
Do lightning rods work?
Yes. Lightning rods, invented by none other than Ben Franklin, neither attract nor repeal lightning bolts. They do, however, provide a safe path to ground for the flash. Indoor plumbing, which includes pipes buried deep in the ground and vents extending above the roof, have long served as surrogate lightning rods for homes. However with the trend towards using PVC rather than metal pipes, this “free” lightning protection has vanished from many newer homes. To be effective, lightning rods must be properly grounded, and there should be no sharp bends in the cable leading from the air terminal (the pointed rod) to the grounding rod.
And now a word from Smoky the Bear about lightning.
Lightning is the leading cause of forest fires in Alaska and the western U.S. In the past decade, over 15,000 lightning-induced fires nationwide have burned over 2 million acres of forest. Thoughtless campers not watching their camp fires and nut cases who like to see things burn are still a major cause of fires, especially near large cities. But still Smoky would like to find some way to help stamp out lightning.
Does it need to be raining for lightning to strike?
It is a myth that if it is not raining there is no danger of being struck by lightning. Bolts can and often do strike as much as ten miles outside of the rain area of the parent storm. Recent research on lightning deaths finds that most fatalities occur in the period when the storm appears to be ending. During the height of most thunderstorms, people are inside seeking protection from the rain. For the ten or more minute period after the rain ends, and even after the sun comes out, lightning is still a threat. People leave their shelters and ....wham! People apparently have enough sense to come in out of the rain, but not always to get out of the way of lightning. Remember, if you can hear thunder, you are close enough to the storm to be struck by lightning. Move at once to a sturdy building or vehicle. GO TO TOP
Can we harness the power of lightning?
Well, first of all “catching” lightning is not the easiest thing to do. But even if could capture and store a bolt, there is less energy there than you might think. Though very powerful while it lasts, the typical stroke only last for millionths of a second. If the total energy of a single lightning flash were captured, it would only run an ordinary household light bulb for several months.
Meanwhile lightning is one reason why U.S. electricity bills are not lower-lightning strikes destroy more than $100 million worth of utility power transformers each year.
Could being struck by lightning be genetic?
Is it in the genes? A midwest woman was struck by lightning in 1995. Nothing odd there, you say. But her nephew had recently been struck and suffered temporary blindness. Her cousin was dazed in the 1970s when lightning struck her unfolded umbrella. The same woman had been struck once before-in 1965. Her grandfather was killed by lightning on his farm in 1921. And his brother was killed while standing in the doorway of his house in the 1920s. At this rate that part of gene pool will soon be exhausted. GO TO TOP
What if you are caught outside in a lightning storm?
If you are caught outside in a lightning storm and can’t make the shelter of a car or building, then get away from isolated trees, tall objects and hilltops. [Being deep inside a grove of trees is safer than being exposed in the open.] Do not be the highest point around. Avoid direct contact with other persons (in a group, don’t hold hands or hug each other!), get into a ditch or shallow depression if possible, crouch down with feet together and with your hands on your knees. Remove metal objects such as belts and golf clubs. And then promise to be more alert to weather signs and not get yourself in such a fix again!
Do we understand everything about atmospheric electricity?
Based on the following story from the truly weird department, apparently not. In 1991, two young girls near Bristol, England were playing frisbee. Suddenly the disk was hurled back at one of the girls by some unseen force. Then both were enveloped in some sort of “yellow bubble.” They received slight electric shocks, were thrown to the ground, and had problems breathing. Eventually they freed themselves from their capture and ran home, quite terrified by their experience.
What is a bolt from the blue?
A bolt from the blue. It is more than just a figure of speech. Lightning bolts can on occasion jump 10 or more miles out from their parent cloud and appear to strike in a region with blue skies overhead. Such was the case on this date in 1995, when lightning struck a ball field near Miami, FL, injuring 10 children and a coach. The skies were clear save for a line of clouds to the distant northwest.
Is lightning sexist?
Lightning seems to be picky about what it hits. Some studies suggest that it preferentially strikes oaks trees over other species. And it certainly is sexist, striking and killing men far more often than women. In Great Britain over a two decade period, 85% of lightning fatalities were men. In a recent study of Florida lightning fatalities, 87% of the persons struck by lightning were males. Before suspecting a plot by radical feminists, note that while 34% of the males struck by lightning were killed, 44% of the females struck died. GO TO TOP
Take cover immediately...
During severe thunderstorms and tornadoes lashing the Huntsville, AL area in February 1995, National Weather Service staff were on television warning people of the dangerous storm conditions. Just then, the weather office took a direct lightning hit a fire started, and the weather radar was knocked off the air.
What is ball lightning?
Ball lightning is one of nature's most mysterious phenomena. Usually seen during violent thunderstorms, the spheres of glowing light are typically the size of bowling balls or basketballs. They can last from a few seconds to many minutes. The spheres can simply vanish into thin air but can also pass through window glass and screens leaving burn marks behind. Not every scientist is convinced the phenomenon even exists. But there are numerous credible reports of "balls" of "fire" floating through the air, often after nearby lightning strikes. They usually do not cause much damage and even seem "playful". They have been known to roll down the aisles of airliners or pass through an open window into a startled resident's bedroom.
On 8 June 1972, a hole, 2 inches across, was punched through a window of an empty office in Scotland during a thunderstorm. Since the glass was melted and fused around both the inside and outside of the pane of glass as well as on the circle of glass found on the nearby floor, it is presumed that ball lightning had passed through the window. Even stranger, the office was in the University of Edinburgh’s Department of Meteorology.
In Wales, on 8 June 1977, a brilliant yellow-green transparent ball bounced down the side of a hillside. It was visible for about 3 seconds but this phenomenon appeared to be the size of a bus!
In 1996 in Gloucestershire, England ball lightning entered a factory. Blue, white and orange, it traveled along girders and machinery around the building, sending off a shower of sparks. The ball then hit a window and disintegrated. The incident lasted only 2 seconds. The only damage was to the company’s phone system, and the nerves of the workers.
Are lightning deaths on the increase?
In the United States, lightning deaths per million citizens have declined some 70% since the 1950s, although the number of serious injuries has only dropped slightly. This is probably the result of several factors, including widespread CPR training which can revive lightning victims.
But with more and larger outdoor gatherings and concerts taking place, outdoor crowds during summer pose a special hazard-the chance of a major lightning strike disaster. On 6 July 1994, at least 22 people were injured as lightning struck a crowded beach in Potterville, Michigan. Some of the victims were in the water. GO TO TOP
If you are not hit directly by lightning, are you safe?
No. Lightning can travel through the ground for a considerable distance from where it strikes. It can easily enter your body through your feet. Four legged creatures like cows and horses are even worse off because they have four feet which are further apart than ours, a fact which increases the electrical potential difference. On 8 June 1993, ten cows were killed by lightning in Trempealeau County, WI. If caught in the open during a thunderstorm, seek shelter from lightning - but not under a cow.
Also lightning might hit a tree nearby, but a phenomenon called side flash can have a streamer jump sideways to a nearby object. Grim photographs exist of a person being directly struck by a bolt followed by a side flash leaping to the person standing several feet away from them. Both were killed. And you could also be on the telephone telling your friends what a neat thunderstorm you are having -when lightning could strike the phone line and travel into phone, and your head. Several people are killed this way each year. Use cordless or cellular phones during lightning storms.
Does carrying an umbrella increase your chances of being hit by lightning?
Probably. But even more risky would be standing next to a boat mast, leaning on a conductive object such as a metal fence, sitting on a railroad track (an already high risk activity) or swimming.
On 31 August 1991, lightning struck two recreational craft in the Gulf of Mexico off Panama City, FL. The toll: 2 killed and 9 injured. Any time you are exposed in a thunderstorm, in particular near a tall, attracting object such as a tree or a boat mast, there is a real risk of being struck by lightning.
How long can a lightning discharge be?
If it is a “cloud-to-ground” bolt, then travel distance is limited by the distance from the interior of the cloud to the ground, which is rarely more than 10 miles. But cloud-to-cloud or intracloud flashes may reach for a 100 miles or more in rare cases. GO TO TOP
A billion dollar lightning strike?
In July 1977, a bolt took out a major power line in upstate New York resulting in a massive 24-hour blackout in New York City. The resulting looting losses were estimated at over $1 billion. There was also a surge in the birth rate nine months later. Maternity costs were not tabulated.
Do cities affect lightning?
Perhaps. Recent research suggests that lightning frequencies over and downwind of a number of midwestern cities can be 10% - 20% or more higher than surrounding areas.
Are mountain climbers at special risk from lightning?
Yes. Falling off a cliff isn’t the only risk for climbers. Between 1980 and 1991, lightning killed at least 50 people in Colorado - and of these 20 were killed while climbing or hiking. Mountain hikers should plan their climbs early in the day before the storms start. If caught in a thunderstorm, don’t stay mounted on horseback. If in a group, spread out. Cars (if you can find one) are a safe haven. Taking shelter under an isolated tree can be deadly, but the cover of a dense forest canopy is relatively safer.
What is keraunophobia?
The irrational fear of lightning is known as keraunophobia. The fear of thunder is termed brontophobia.
What is the most dangerous part of a lightning storm?
Near the end. A study of Florida lightning strike casualties found that the largest number occurred just as the storm was ending, not during its most intense part. Seems people were to quick to declare the storm “over” and wandered outside from their protective shelters to get nailed by the storm’s last flashes. GO TO TOP
Ugly Luck Department:
Lightning struck a Waterford, WI barn on July 10, 1992. Inside the barn were 6000 bales of hay.
During the 1990s, roast chicken became a staple of fast food restaurants. And in July, 1995 in Miller City, OH nature joined the trend when lightning struck a poultry farm and 68,000 chickens were roasted.
In 1926, the Navy's largest ammunition depot was located in Lake Denmark, NY. The storage buildings were sturdy, and equipped with lightning rods. On 10 July, lightning struck. BLAM! Depth charges and TNT bombs went off. Sometimes you just can't argue with Mother Nature.
On July 2, 1992 in the Chicago area the fireworks started early. Five people were killed by lightning. Then thousands were left in the dark for up to two days due to widespread, storm-caused power outages.
Strike 1: Lightning strikes a chemical plant in Texas. Strike 2: The building catches fire. Strike 3: The fire department finds there isn’t sufficient water available to put out the fire and the place goes up in flames.
The summer of 1980 was a rough one for lightning strikes in Ohio. In Wickliffe, the entire high school football team was knocked down by a bolt during practice, and one player was injured. Then 26 people were injured in Tuscora Park, OK, with one fatality. And a lone man was struck and killed - while digging a grave in a cemetery.
Lightning struck near a house in upstate New York on 17 July 1988. Among the unusual results: the tires on cars parked in the driveway were flat. The hubcaps were blown off. And the home owner's contact lens popped out of his eye.
What is heat lightning?
Heat lightning is not a special form of lightning. It is simply the reflection of regular lightning off atmospheric dust layers from distant thunderstorms below the horizon. GO TO TOP
Can you outrace lightning?
The electrical breakdown of the atmosphere during a lightning strike takes place at speeds on the order of 100,000 miles per second. You can hide but you can’t run from Zeus.
What if you hair stands on end?
If you are outside when a thunderstorm is nearby and your hair starts to stand on end, a fishing line literally hangs in the air after casting, or a plastic rain coat suddenly begins lifting into the air, lightning may be about to strike. These phenomena are caused by an extremely high electric field in the atmosphere. Seek shelter immediately. If caught in the open, crouch down as close to the ground as possible without having your hands touch the ground.
What is triggered lightning?
On March 26, 1987, the Air Force launched a rocket from the Kennedy Space Center carrying a communications satellite into low-hanging rain clouds. 48 seconds after launch, the rocket was "struck" by lightning - apparently triggered by the ionized exhaust plume trailing behind the rocket. The cost: $162 million dollars (which was not insured except by the taxpayers). A similar thing happened to the Apollo moon landing launch vehicle during lift off, although the mission continued without incident. Also, scientists routinely fire small rockets trailing copper wires into electrically charged clouds, often triggering a lightning strike in a predetermined location. This capability is being used to study the effects of lightning on electrical equipment and materials, as well as to conduct atmospheric research.
Can you get paid to be struck by lightning?
Some research pilots actually did. Their job was to fly heavily instrumented F106 aircraft through thunderstorms, deliberately trying to be struck by lightning. And they were really good at their job, getting nailed many times. This seemingly odd occupation was pursued to improve aircraft lightning safety features and to develop better forecasting tools for in-route lightning avoidance. Too bad the old TV show “What’s My Line” still isn’t on the air. These guys would be shoo-ins.
Can you sit under a tree that grows in Brooklyn?
Yes, but not during a thunderstorm. On 9 July 1988, one man was killed and ten were injured during a thunderstorm in Prospect Park, Brooklyn, NY, while seeking "shelter" under a tree. Standing under or near a tree during a thunderstorm is truly dangerous. Nationwide, dozens of people are killed and injured each year as a result.
Does thunder make milk go sour?
An "old wives tale" says that thunder causes milk to go sour. Neither thunder nor lightning can have that effect. Nevertheless, the thunderstorm season comes with heat and humidity, and if not properly refrigerated, milk will "turn" sooner than usual, thunderstorms or not.
Want to try an electrifying new experience?
Take a vacation. Go hiking in the Colorado Rockies. Climb to near the top of a tall peak to admire the view, and stand there during a thunderstorm. A Massachusetts woman did just that in the summer of 1991. She also had the good sense to be struck by a lightning bolt right in the presence of a doctor and a nurse. They revived her stopped heart with cardiopulmonary resuscitation. Somehow this makes bungee jumping seem perfectly tame by comparison. For those less adventurous, heed the signs posted by the Forest Service, which suggests among other things to do one’s mountain climbing early in the day before the afternoon thunder (lightning) storms get going. GO TO TOP
How loud is thunder?
Sound intensity can be expressed in decibels (sometimes abbreviated dBA). A clap of thunder can typically register about 120 dBA, or ten times louder than a garbage truck, chain saw or pneumatic drill. On the other hand, sitting in front of the speakers at a rock concert can expose you to a nearly continuous 120 dBA, which can seriously harm your hearing.
Things that go boom at the beach?
One enduring mystery has been the reports by coastal residents of “water guns,” loud thunder-like booms that seem to emanate from somewhere out over the sea. The reports have been made for centuries, so sonic booms seem to be ruled out. Natural gas explosions are one possibility.
What are mistpouffers?
We don’t know. They are one of the great mysteries of 19th century science, and still unexplained. Mistpouffer? One of the many names given to strange, dull, distant, explosion-like sounds that have been heard sporadically along the coasts of Europe and elsewhere, with no apparent cause.
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2007-04-30 02:25:40
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answer #10
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answered by Billie Jean 5
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