Lightning

[rocketsocks]

This is correct. When lightning contacts earth, charge flows through earth and causes current at a distance from the point of contact. When current flows through a resistor, there is voltage. Earth has high resistance, therefore high voltage across a given distance. When the "step potential" (voltage across the distance of your stride) exceeds hundred of volts, as is common with lightning currents, anything touching the ground in two points across that distance is in trouble.

Nothing will protect you from a direct strike. But "step potentials" of hundreds of volts can be survived with a dry foam pad.

Most decent literature will also tell you if you are caught in the open to crouch with your feet together. Same reason.

I suppose if you run, you're in good shape because you're only touching the ground with one foot at a time. That's probably not on your mind if you're running away from lightning, though. And running downhill with a backpack introduces other risks.

I used to design substation grounding grids that reduced step potentials to protect workers exposed to high ground currents during power line faults. Sometimes we provided insulating platforms at switch handles. That's why I feel a foam pad is sometimes the best place to be in a risky situation.

Yup, and that's why they say make your foot print as small as possible by crouching and keeping your feet together. One problem I encounter with this is when I try to do that, I inevitably end up starting to fall over and to keep my balance place a hand on the ground away from my feet (kinda like playing the game twister) but in doing so I just set up that condition again of stride so to speak, or step voltage by increasing my over all foot print. For me I'd just sit (dare I say) Indian style on a pad, it's a bigger foot print, Butt I'm not in risk of falling over and having to place an additional hand o the ground increasing the resistance across my body. Good points Garlic, I just learned about step voltage a couple years ago, the why fors and how comes.

Post Script But, if one is limber, spry, and with good balance while on the balls of their feet, then yes that is the best thinking of the day.

[rocketsocks]

this image illustrates quite nicely I think the condition of step or difference in voltages. lightning3.jpg

[Twogears]

......if it ever gets that close I will stow my pack, get 100 feet or more away from it and crouch down or find a low spot to ride it out.

What would the purpose of ditching your pack be? I would keep it with me to use, potentially, to protect from the hail that is likely to occur with the storm.

Safest places are gently rolling terrain with uniform height trees and dry ravines or deep depressions.

[RED-DOG]

the thing is when a person is on a long distance hike such as a thru the person can't choose where he/she is going to be when a storm strikes, the thing to do if you on a ridge line or going across an exposed Bald is to find cover and to deal with it the best you can, I have always just kept hiking until the next shelter then got out of it, I personally have been through some really bad thunderstorms, the best thing to do is to find cover.

[magneto]

I don't usually comment on threads like this, but I feel it is important. No sleeping or tent is going to protect you from a lightning strike. Setting up your tent in an electrical storm and laying on your sleeping pad is asking to die. Do not do it. A lightning bolt has a potential of a million volts or more and the current can be measured in thousands or hundreds of thousands of amperes. The only reason you are safe in a car or other metal structure is because of so-called "skin effect". Lightning is has a very high frequency (quick on then off), so the electric current it does not penetrate very far into a conductor like the metal of a car. The charge stays on the outside of the metal frame, away from you, and travels to ground through the tires. The tires do not in any way insulate the car.

For more information, see this link:

http://www.mos.org/live-presentations/lightning

You can see an example of "skin effect" in action.

If you are caught above treeline in a thunderstorm, the best thing to do is keep moving towards the trees. Do not stop. If you sense that you are about to be struck, crouching on the ground as low as possible with only your feet in contact with the ground to minimize the damage is the recommended procedure. This is known as the "Lightning Position". You can crouch on your pad if it makes you more comfortable (so you can hold the position long) See here:

http://rendezvous.nols.edu/files/Cur...Guidelines.pdf

and here:

http://www.lightningsafety.noaa.gov/outdoors.htm#near

[K6VOI]

I have read up on all the provided lightning safety links everyone provided and read all your good advice. We have hiked in the Sierra's for decades and have always been very cautious when proceeding up a pass. If a storm is brewing we don't go. We usually always try to hit passes in the morning. It seems that the CT has more of a danger of lightning strikes than the Sierra's - at least what I am reading.

So, if we hit passes by noon, should we generally be safe? I understand to watch storm patterns. I just know that at sometime during our 35 day CT hike, we may be in the wrong place at the wrong time - a pass, clouds roll in fast - so hike down to trees as fast as you can? The people that were hit by lightning this past weekend, I read they had thunder all around them, and proceeded to quickly hike down, but they were struck. I guess it matters how far the thunder is from you (the 30/30 rule)? If you are suddenly caught in a thunderstorm above tree line and lightning is a real danger, just crouch in the lightning position until the storm is over? I mean one can't crouch like that for an hour right? Does a sleeping pad that is not foam help to crouch on? Our are the inflatable type.

I guess the best thing to do for us, is to ALWAYS be at a pass by noon, and get down quickly. I have the weather bug app with the Sparks lightning notification but I think you need a 3G signal (it does not just work on GPS) - so it won't be that helpful on the trail most of the time.

And here I was worried about cougars on the trail!!!!

[SawnieRobertson]

I grew up Catholic. Curiously, when lightning is nearby, knowing the words to the Hail Mary comes back to me in full force.

Thanks for that addition to the conversation. The Lords Prayer also brings calm. Things get into perspective.

[bearcreek]

Colorado averages 2.8 fatalities per year due to lightning. (This year may be higher) Last year 481 people were killed in automobile accidents. (Be careful when driving to the trailhead) The average number killed skiing at ski areas is 12. Avalanches killed 14 in CO this past season. 14 drowning deaths so far this year. Mountaineering falls claim 8 or more annually.

If you have climbed any 14r's recently, then you have probably seen the large groups of people waiting in line to summit. There are thousands of people out there but lightning accidents remain one of the less common events.

Most lightning hits the high points, and most strikes happen in the afternoon. The simple solution is to avoid the high points in the afternoon when the weather is sketchy. The CT really has a lot of big ups and downs, and a little planning can really help.

Those high points don't have to be above timberline. The idea that being in a forest is some sort of protection is not necessarily valid. Forested ridges at lower elevations receive a lot of strikes whenever they are the tallest thing around. If you are hiking in forest and notice a lot of trees have evidence of lightning strikes (a scar in the bark running from top to bottom) then that may not be a particularly good place to seek shelter.

[Wise Old Owl]

I don't usually comment on threads like this, but I feel it is important. No sleeping or tent is going to protect you from a lightning strike. Setting up your tent in an electrical storm and laying on your sleeping pad is asking to die. Do not do it. A lightning bolt has a potential of a million volts or more and the current can be measured in thousands or hundreds of thousands of amperes. The only reason you are safe in a car or other metal structure is because of so-called "skin effect". Lightning is has a very high frequency (quick on then off), so the electric current it does not penetrate very far into a conductor like the metal of a car. The charge stays on the outside of the metal frame, away from you, and travels to ground through the tires. The tires do not in any way insulate the car.

For more information, see this link:

http://www.mos.org/live-presentations/lightning

You can see an example of "skin effect" in action.

If you are caught above treeline in a thunderstorm, the best thing to do is keep moving towards the trees. Do not stop. If you sense that you are about to be struck, crouching on the ground as low as possible with only your feet in contact with the ground to minimize the damage is the recommended procedure. This is known as the "Lightning Position". You can crouch on your pad if it makes you more comfortable (so you can hold the position long) See here:

http://rendezvous.nols.edu/files/Cur...Guidelines.pdf

and here:

http://www.lightningsafety.noaa.gov/outdoors.htm#near

excellent post... I like it... thanks..

http://en.wikipedia.org/wiki/Dielectric_strength

[garlic08]

I have read up on all the provided lightning safety links everyone provided and read all your good advice. We have hiked in the Sierra's for decades and have always been very cautious when proceeding up a pass. If a storm is brewing we don't go. We usually always try to hit passes in the morning. It seems that the CT has more of a danger of lightning strikes than the Sierra's - at least what I am reading.

It's a little funny you mention that. I hike mostly in CO, and on my PCT hike I never felt as threatened by lightning in CA. It seemed most afternoon storms in the Sierra had cloud-to-cloud lightning. I never investigated that further, assuming it was an aberration.

So, if we hit passes by noon, should we generally be safe?.

Yes, though there are exceptions, of course. As I type this before 6 am in the Front Range, there is thunder outside.

...If you are suddenly caught in a thunderstorm above tree line and lightning is a real danger, just crouch in the lightning position until the storm is over? I mean one can't crouch like that for an hour right? Does a sleeping pad that is not foam help to crouch on? Our are the inflatable type.

Theoretically, if you have nowhere to descend to safely and in a timely manner (sometimes the case on the long CT ridge walks), that's a safe position. But you're right, you can't do that for an hour in freezing rain and gusting wind--hypothermia might be a greater danger than lightning. I did that once and it was no fun at all. In those cases (this has happened twice in half a lifetime of hiking the high country), I'll find the safest place around (off the highest point) and pitch my shelter to keep dry, get on my dry pad, and wait it out. (If I don't have my shelter with me, I'm on a different kind of hike and would not be up there in the first place--I finally learned my lesson.) Any inflatable or CCF pad will have some dry insulation between you and the ground, so you should be safe from step voltage.

Of course, as pointed out, nothing will protect you from a direct strike. But very few people win the lottery, too, to paraphrase Bear Creek. The odds are in your favor in this case.

It's not a good situation, and usually good planning will keep you from experiencing it, but sometimes $#!& happens, the weather does not behave as you'd thought it might, (like this morning) and you need to do the best you can to minimize your risk.

Something nobody has pointed out here, though covered in the literature, is if you are in a group, spread out but keep eyes on each other. You don't want the whole group to be disabled in case of a nearby strike.

[skyview]

Thanks for the comments and lightning safety advise!
Im still torn about the hike, as unfortunately, the hikes runs about 18 miles per day (4 days of hiking to cover 72 miles --- this is a group hike so I do not control the distances needed to be covered each day), and timing wise puts me at highs pots on the trail 3 of the 4 days during the afternoon... this leaves me uneasy in that I agree, that type of planning puts one at risk for the afternoon thunderstorms.... which goes against all Ive learned, do not be on the higher spots in the afternoon, but thats exactly how this hike will play out... even starting at 5-6am Im only good for about 1.8 miles per hour avg.

[Dogwood]

Can we now explore the feel good vibes around waterfalls resulting from negative ions?

[rocketsocks]

Can we now explore the feel good vibes around waterfalls resulting from negative ions?

Yes, and how the colors of the rainbow effect our firing and dopamine levels...good stuffs.

[Dutch1976]

Thanks for the comments and lightning safety advise!
Im still torn about the hike, as unfortunately, the hikes runs about 18 miles per day (4 days of hiking to cover 72 miles --- this is a group hike so I do not control the distances needed to be covered each day), and timing wise puts me at highs pots on the trail 3 of the 4 days during the afternoon... this leaves me uneasy in that I agree, that type of planning puts one at risk for the afternoon thunderstorms.... which goes against all Ive learned, do not be on the higher spots in the afternoon, but thats exactly how this hike will play out... even starting at 5-6am Im only good for about 1.8 miles per hour avg.

The idea of Lyme disease on the AT freaks me out a little bit. Lightning on the CT freaks you out a little bit.

With preparation and being armed with the knowledge of how to minimize risk...Neither one of us should really be freaked out.

[magneto]

You need three things for a thunderstorm to develop: moisture in the atmosphere, an unstable temperature lapse rate and an initial source of lift to start the process.

With a little planning and info, you can learn to predict times when one or more of the three requirements are missing. You don't get storms every day - it is possible to avoid them.


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[SawnieRobertson]

You need three things for a thunderstorm to develop: moisture in the atmosphere, an unstable temperature lapse rate and an initial source of lift to start the process.

With a little planning and info, you can learn to predict times when one or more of the three requirements are missing. You don't get storms every day - it is possible to avoid them.


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Ha! Obviously you have not spent a summer in the higher elevations of the Rockies. Some weeks the storms come just about every day, and each of them is as BIG as it was unpredictable. This is mountain conditions forecasting. It is one thing to backpack on your own, not having to conform to the sometimes outrageously ill-informed decisions of others and quite another to use one's own grey cells (for their protection). The other thing mentioned is insecurity about the distance the OP is able to move per hour. That can bring on difficulties that the others do not deserve too. There is an old, wise saying:
"WHEN IN DOUBT, DON'T."

[Coffee]

I'm planning to be prepared and use common sense but ultimately the weather is just part of the hike and a risk that has to be accepted. The probability of being struck by lightning can be reduced with some precautions but not eliminated but that's just like countless other risks that people take every day, whether they are conscious of the risks or not.

[magneto]

Just go on your own and use your brain. If you feel uncomfortable, don't go. Don't hike with a group you don't trust.




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[Coffee]

I've built in three planned zero days, two low mileage days and a slack day before my flight out of Durango and I'm going to be prepared to adjust my schedule and sacrifice zero/nero days if needed to avoid dangerous weather. Leaving some slack time to avoid being "forced" to go over passes in bad weather due to schedule issues is one way to minimize the temptation to make poor choices.

[magneto]

Coffee-

That sounds like a good plan. If you hear thunder - just wait till the storm passes. Hike in the early AM - hike after dark or before sunrise using the light of the moon and stars or use a headlamp.

You can find apps and tables on line to see moon rise/set time and phase.

You have options.


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