Lightning Safety Facts

[bobby49]

In a lightning engineering class, they teach you that any high target for lightning, like a peak, provides a theoretical 60-degree cone of protection underneath it. The operative word there is _theoretical_.

[dil950]

Thanks for the clarification…definitely going to keep my eyes on the clouds before heading to some of the lakes around there. Thanks again

[SSSdave]

Hi! Great read for somebody starting to venture further into the high country. One thing I’m not too clear of is what do you do if you’re basically in a 10k basin? I plan on camping around Muriel lake and it looks like there’s not much in terms of dense tree cover. If a thunderstorm starts, is it considered lower already, since there are higher peaks around it? Or is it better to go a bit lower, like golden trout lakes, if there is a chance of storms. Thanks for any insight.


After looking at the topo and Google Earth. The magenta areas would be safest at the foot of steep slopes where drier sandy granite soils mix with talus. All look like they are likely tentable. Ochre areas are where most backpackers camp as one would expect. I weathered a lively storm there and many others have apparently haha though it is no where as safe as the lower purple areas.

Muriel2.jpg

Muriel1.jpg

View from above the purple area under my topo U in Humphreys. Large whitebark pines in safe places to tent behind with afternoon shade and pleasant places in the creek for dunkings, few use because trails are on the other side of the creek.

[BigMan]

Check out these lightning close calls: https://www.youtube.com/watch?v=3f7zNJ3nL9M

"When I watch this video, you know it always brings me down."

- Ronnie James Dio

[SSSdave]

To be honest, when I know I am not in a safe location, lightning scares me strongly. When I know I'm in a safe place in the landscape, I say "bring on the show!" But even then, any strikes near my position will soon have me in a much more serious mood. And much of that is because I worked with electronic phenomenon all my adult life and have modestly studied it's science a long time. For those that understand little, Ignorance is bliss.

Great video ( Almost Struck by Lightning Compilation ) and funny in parts. The one with the tree hit in front of those red cabins was impressive. That guy that runs out to his red car with an umbrella runs back without completing his mission.

On the below link, lower down from the morning work, I describe escaping from a thunderstorm with lots of bolts that overtook my position hiking out with a heavy pack along large Dorothy Lake up Convict Creek.

https://www.davidsenesac.com/2020_Trip_ ... html#jul24

[generalelectrix]

The more I read about it, the more it seems like lightning is just a straight-up unmanageable risk in the backcountry; if you're in the presence of a thunderstorm, there is no truly safe place if you are outside. Thankfully, the risk is very, very small, because the landscape is very large, the number of lighting strikes are relatively few, and as you can see from so many instances in that video compilation, you can be remarkably close to a lightning strike and be perfectly fine. Statistics are the only thing that truly keep us safe from lightning in the mountains if thunderstorms are around. Not being on a peak or ridge is probably still a good idea.

You might feel safer in the forest at 8000 feet compared to an "exposed" basin at treeline at 10,000 feet, but "lower" elevation and not being "exposed" did nothing for these people:
https://www.fresnobee.com/news/local/ar ... 12033.html
https://www.mymotherlode.com/news/local ... death.html

[Wahiker9]

Thank you for so much good info in this thread. I have read through the posts several times – to the point where I now look around while on my hikes and think about what may or may not be good spots to wait out storms. I am preparing for a NOBO JMT hike mid-July. I know lightning strikes high and low but am trying to minimize risk by getting as much of an understanding as possible and hopefully making wise choices. Last late-July while camped in Mehrten Meadow, I experienced the most terrifying series of late afternoon/evening T-storms ever – sheets of hail, near simultaneous lightning/thunder. In photos, I realized that I’d pitched my tent right up against two large conifer tree trunks – I think when site choosing the trees gave some weird sense of security…will not do that this time around. There are still a couple of things I’m unclear on and would love any info that would help my understanding.
Using Mehrten as an example: there were sites within the trees/forest, but not completely covered by the canopy – open to sky directly above – and about 10 – 15 feet from any tree trunk; would this type of area be a preferable place to set up as opposed to right next to a tree? (May be dumb but my thinking of those sites was that my tent would be the tallest thing in that immediate area.)
Am I right in understanding one of the posts, that setting up near the Whitebark pines that occur near the higher lake areas can be relatively, okay? Or only if they are at the base of a steep-ish slope? Or should I always just try to aim for lower elevations/thicker forests? (Areas which still have risks.)
Any other specific info or suggestions would be appreciated. (Apologies for sounding rather basic – I am definitely not a scientific type of person.)
Thank you for any additional insight.

[bobby49]

Lightning tends to try to strike to ground to expend its energy. It tends to ignore anything that is non-conductive, and it tends to hit something conductive. A tree of any kind tends to have its roots down into conductive soil (ground), so if the lightning can strike a tree, then its energy is expended. If you have ever studied a lightning strike on a tree, the energy tends to follow the vasculature of the tree down into the roots. Sometimes that is within the core of the tree, and sometimes that is nearer to the bark. So, a stand-alone tree is a good thing to stay away from during a storm. On the other hand, lightning tends to hit somewhere around the highest point of a cluster of trees, so just don't be next to that highest point. If you are out in the open with no trees around, then standing upright is dangerous during the storm. The advice is to lay down flat in a depression so that you are not the most obvious target. Rocky peaks and cliffs will be struck, especially if the rocks are wet from rain.

[Harlen]

We read somewhere that squating with just your feet on your foam pad was also a good position. Less body contacting the ground. I hope bobby49's position is right, as it would be more comfortable.

[Gogd]

Looking like I may get some promising lake reflection photo ops on our Silver Divide trip about Graveyard Lakes and the big lakes across the divide. Just weighed my pack and carrying weight at 65 pounds. Its a beast.

LOL! The closest I've come to being struck by a bolt was camping at the lowest of the Graveyard Lakes. We were fishing when it started to thunder, so I went back to camp, situated in the dense stand of trees along the southeast bank of the lake. Mid storm a bolt touched the middle of the lake, then moments later another struck a tree about 20 yards from our camp. My advice: camp along the north end of the lake or further up the basin. That lake sits at the mouth of the Graveyard Lakes basin. This basin is just below the crest line of the Silver Divide, which will imped weather traveling out of the substantial canyon below below Graveyard Lakes, which contains Lake Thomas Edison. The LTE basin is notorious for channeling storms into the High Sierra. The mouth of hanging valleys (e.g. Graveyard Lakes basin) are known to generate lots of air turbulence, thus cause electrical events. The large number of trees scared by strikes at the mouth of the Graveyard Lakes basin are testament that lightning strikes are a risk factor of the nearby vicinity.

Ed