The Safest Thing to Do On an Open Field During Lightning

[stevmg]

As in the the title, what to do if caught in an open field during a sudden lightning storm. Have heard conflicting recommendations from laying flat to squatting in two feet. Trying to avoid being part of the return strike which would not be pleasant at all.

 

[tech99]

As in the the title, what to do if caught in an open field during a sudden lightning storm. Have heard conflicting recommendations from laying flat to squatting in two feet. Trying to avoid being part of the return strike which would not be pleasant at all.

Two mechanisms at work here.
1) For a direct strike, it is thought that strike locations are random, say 1 strike per sq km per year, but tend to be drawn to an object over a radius equal to its height. So if you halve your height, the area over which you might draw a strike is then a quarter.
2) When the strike hits the ground, very large currents flow outwards in the ground and create a voltage gradient across the ground. This gradient can drive a current through an animal whose legs are at different points. Four legged animals are more at risk than man, as the voltage is greater due to the spacing.
For this reason, crouching low with feet together is recommended. Walking has the advantage that the feet are both in contact with the ground for a very small period. Other advice is to stay away from a long fence, which has a high statistical risk of being struck, and from a tree, which will have large ground currents and a risk of side flashing. As for removing metal objects, this is official advice but I am uncertain of the theoretical basis.

 

[stevmg]

@tech99. Your blog appears to be succinct and to the point with excellent examples and common sense. I will leave this string open for a while but really don't anticipate a better or more informative reply than yours. The only question I have is that if my height is six feet, half my height is three feet and then? Are you saying that a direct strike would be more likely if I were three feet wide? I don't understand that part of your reply. The second part is crystal clear.

 

[tech99]

@tech99. Your blog appears to be succinct and to the point with excellent examples and common sense. I will leave this string open for a while but really don't anticipate a better or more informative reply than yours. The only question I have is that if my height is six feet, half my height is three feet and then? Are you saying that a direct strike would be more likely if I were three feet wide? I don't understand that part of your reply. The second part is crystal clear.

Thank you Steve. If an object, such as a pole, is six feet high, then we expect it to collect lightning strikes from a ground area having a radius of six feet. If it is three feet high, then it will collect from a 3 ft radius. In the second case, the ground area is a quarter of the first, so by halving the height, the chance of a strike is quartered. If an object is wide, such as a building, then it is assumed that the capture area is the actual area, plus a surrounding margin worked out from the height, as I have described.

 

[Evo]

To clear up misinformation about lightning stikes if caught in an open field.

If you are caught outside in a storm, always look for appropriate shelter. Do not take any chances -- lightning can use you as a path to the Earth just as easily as it can use any other object. Appropriate shelter would be a building or a car (see the "lightning myth" sidebar at the bottom of the page to find out why).

What should I do if I'm caught out in the open during a thunderstorm and no shelter is nearby?
There are NO SAFE PLACES outdoors during a lightning storm. Don't kid yourself--you are NOT safe outside. Following these tips will not prevent you from being struck by lightning, but may slightly lessen the odds.

Shouldn't I lie flat on the ground to get as low as possible?
NO! Lying flat on the ground was once thought to be the best course of action, but this advice is now decades out of date. When lightning strikes the earth, it induces currents in the ground that can be fatal up to 100 feet away. These currents fan out from the strike center in a tendril pattern, so in order to minimize your chance of being struck, you have to minimize BOTH your height AND your body's contact with the Earth's surface.

How do I avoid having to use the Lightning Crouch?
We don't recommend the crouch because it will not significantly lower your risk of being killed or injured from a nearby lightning strike.
Be aware of your situation and PLAN AHEAD. If you going to be involved in an outdoor activity, make sure you know what the forecast is, ESPECIALLY if you live in a lightning prone area. If storms are forecast, have a plan of action that you can enact quickly to reduce your chances of being struck.

http://www.srh.noaa.gov/jetstream/lightning/lightning_faq.htm

http://science.howstuffworks.com/nature/natural-disasters/lightning8.htm is a nice lengthy read.

Why am I so interested in lightning? I have been struck 3 times, twice on a corded phone, where the phone was blown out of my hand and across the room, yes I suffered hearing loss which eventually returned. Once from plumbing. I saw the lightning hit in the yard and dirt fly up into the air. then I was getting into my car once and had just sat in the car and closed the door when the hair on my head and neck went up and the lightning hit a few yards away. My house was directly hit by lightning, had a small electrical wire fire in the walls, lost $10k in electronics, burnt out the power surge protectors too, yes I have threads about these when they happened which I wrote here years ago. The oldies here might remember my streaks of incredibly bad luck.

 

[davenn]

The oldies here might remember my streaks of incredibly bad luck.

But hey ... The good luck part is ... even after all that, you are still with us :)
ThankfullyDave

 

[Evo]

But hey ... The good luck part is ... even after all that, you are still with us :)
ThankfullyDave

What? What was that you said sonny? Speak into old Evo's other ear.

 

[tom aaron]

I personally don't think about it. About 25 people are killed each year in the USA by lightning. That's less than 1 person in 10 million.

I don't live where Evo lives, so the odds for me must be near zilch.

Having said that...fields are relatively safe. Nearly all lightning fatalities involve trees, roofs, etc. Yes lowering your stature may help... and having minimal ground contact. I doubt if there is any means of measuring any stats. However, it's all physics so Tech99's advice seems valid to reduce an unlikely event even more.

Nobody in decades in my area has been killed walking in a field in a lightning storm.

 

[davenn]

What? What was that you said sonny? Speak into old Evo's other ear.

LOL

I don't expect you to divulge, but I turn 56 in 3 days time. My "sonny" days are well behind me

Dave

 

[stevmg]

Thank you Steve. If an object, such as a pole, is six feet high, then we expect it to collect lightning strikes from a ground area having a radius of six feet. If it is three feet high, then it will collect from a 3 ft radius. In the second case, the ground area is a quarter of the first, so by halving the height, the chance of a strike is quartered. If an object is wide, such as a building, then it is assumed that the capture area is the actual area, plus a surrounding margin worked out from the height, as I have described.

My problem, @tech 99, is that have such a fat head, that lightning would hit it before it hit the ground. However, I think you have quite adequately answered this question and I have to contact Evo on how to close this thread. Mucho thanks for your help.

 

[stevmg]

@Evo. I know a woman (a red head, naturally) who has been struck by lightning three times. She is crazier than a hoot owl but I am positive that her craziness preceded her lightning strikes. She had to be that way as there is no earthly explanation as her complete lunacy, although the good news is that she is "nice crazy" and makes everyone around her laugh.. I think your hair rising up just prior to the lightning strike near you was the build up of static electricity from the ?streamer effect with like charges which repelled each other. We had a lightning strike some 20 feet from our house which blew out all the phones, the flat screen TV, an older computer. Fortunately, the TV was still on mfg. warranty, the phones were the responsibility of the cable company, and the computer I had to upgrade anyway, just forced me to do it a little earlier. You mention to avoid the lightning crouch position, but what do you do (I don't go outside during electrical storms) when you're stuck. Laying down is no good, crouching is no good. Anything good, other than prayer?

 

[stevmg]

@Evo. Then, in your understanding, what are the "positively charged particles" which travel upward (in the streamer) towards the stepped ladder? They are not electrons, they are not positrons. Maybe they are positively charged ions or atomic nuclei after their electrons have been stripped (plasma). Maybe it is the charge, not the actual particle that moves up much like a freight train initially pulls the last car but the train itself does not move the entire length of itself. Do I make sense now?

 

[Evo]

I'm not a scientist, I've just always enjoyed science, but my dad wouldn't allow me to go into science, (long story), so I surrounded my self with people in science, not hard since I lived near NASA and studied on my own with their help. What I am now is a "googler". What I found is this, which I previously posted, perhaps someone here can explain in more detail.

• Even the positive streamer launched by the ground is really only made up of positively charged air particles because the electron(s) left the particle.

http://www.regentsprep.org/Regents/physics/phys03/alightnin/default.htm

This was also interesting. http://www.physicsclassroom.com/class/estatics/Lesson-4/Lightning

 

[stevmg]

@Evo. It seems like the first if your references answers the questions: there it is stated:

"

• As the negative charges collect at the bottom of the cloud it forces the negative charges in the ground to be forced away from the surface. This leaves the ground positive.
• A streamer of negative charges is repelled by the bottom of the cloud and attracted by the ground.
• As this streamer of negative charges approaches the ground, a streamer of positive charges is repelled by the ground and attracted to the negative streamer.
• When the two streamers connect, they have created a fairly conductive path which allows a sudden down surge of electrons to jump to the ground. This is the lightning.
• The rapidly moving electrons excite the air along the path so much that it emits light. It also heats the air so intensely that it rapidly expands creating thunder.
• One thing to notice is that the positive charges that make up both the cloud and the ground do not move. Even the positive streamer launched by the ground is really only made up of positively charged air particles because the electron(s) left the particle.

The last bullet answers the question. It appears that a charge can move without (significant) movement of particles. But, BAM! When the streamer meets the stepped ladder, the electrons do move in the order of 10^5 mph while the electric field itself moves almost at the speed of light:
https://www.physicsforums.com/threads/speed-of-electricity.322195/

This was never very clear to me and most references, other than the few I have found and some others which were pointed out to me actually addressed this phenomenon. Sometimes the simplest question defies a simple answer, if any.

 

[Windadct]

SO apparently I found the best position - no everybody practice this.

 

[mfb]

Above the ground, with a large cross-section, and if lightning strikes the whole current will flow through the arm. Does not look very safe. On the other hand, if you get struck, you can think "no problem, it's just in my head" - unless it actually was in your head, then you probably cannot think any more.

 

[stevmg]

SO apparently I found the best position - no everybody practice this.

She is s-o-o-o skinny - ugh!

 

[msrlasky]

The odds of being hit by lightening, (from Aaron's comment ~1 in 10 million) when a large fraction of the population is indoors when it's raining, is too simplistic for me. The odds of being hit by lightening, when lightning is present, and you are outdoors, is a more useful statistic, and while I've never seen those odds, I wouldn't take the risk lightly (pun intended), and strongly suspect that it's much higher, or IMO, the odds of several commentators here having had experiences with lightning strikes would be statistically rather peculiar. Also, if you feel a static charge, run like heck; and for groups of people; run in as many different directions as possible so that if one person is hit, the others can be of assistance. I wonder if planting my aluminum walking stick in the ground just before I do the 400 meters, might improve the odds?