About Lightning & your experiences

[David777]

Expect we all have some fascinating lightning stories. I backpack into High Sierra wilderness that has lots of lightning during summer within certain weather patterns as Mexican Monsoon flows, especially with small hail, torrential rain, and sometimes snow at night. For those that have time to read the fascinating science:

Why lightning occurs:

Lightning detection - Wikipedia

Storm location: Even in daylight, "storm chasers" can use directional optical detectors that can be pointed at an individual cloud to distinguish thunderclouds at a distance. This is particularly important for identifying the strongest thunderstorms which produce tornadoes, since such storms produce higher flash rates with more high frequency radiation than weaker non-tornadic storms

Microburst prediction: IC flash detection also provides a method for predicting microbursts.  The updraft in convective cells starts to become electrified when it reaches altitudes sufficiently cold so that mixed phase hydrometeors (water and ice particles) can exist in the same volume. Electrification occurs due to collisions between ice particles and water drops or water coated ice particles.

The lighter ice particles (snow) are charged positively and carried to the upper portion of the cloud leaving behind the negatively charged water drops in the central part of the cloud.  These two charge centers create an electric field leading to lightning formation. The updraft continues until all the liquid water is converted to ice, which releases latent heat driving the updraft. When all the water is converted, the updraft collapses rapidly as does the lightning rate.

Thus the increase in lightning rate to a large value, mostly due to IC discharges, followed by a rapid dropoff in rate provides a characteristic signal of the collapse of the updraft which carries particles downward in a downburst. When the ice particles reach warmer temperatures near cloudbase they melt causing atmospheric cooling; likewise, the water drops evaporate, also causing cooling. This cooling increases air density which is the driving force for microbursts. The cool air in "gust fronts" often experienced near thunderstorms is caused by this mechanism.

Storm identification/tracking: Some thunderstorms, identified by IC detection and observation, make no CG flashes and would not be detected with a CG sensing system. IC flashes also are many times as frequent as CG so provide a more robust signal. The relative high density (number per unit area) of IC flashes allows convective cells to be identified when mapping lightning whereas CG lightning are too few and far between to identify cells which typically are about 5 km in diameter. In the late stages of a storm the CG flash activity subsides and the storm may appear to have ended—but generally there still is IC activity going on in the residue mid-altitude and higher cirrus anvil clouds, so the potential for CG lightning still exists.
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Types of lightning:

Lightning Types

Does lightning go up or down? There are two ways that flashes can strike ground: naturally downward (those that occur because of normal electrification in the environment), and artificially initiated or triggered upward. Artificially initiated lightning is associated with things like very tall structures, rockets and towers. Triggered lightning starts at the “ground,” which in this case may mean the top of a tower, and travels upward into the cloud, while “natural” lightning starts in the cloud and travels to ground. Upward triggered lightning usually occurs in response to a natural lightning flash, but on rare occasions can be “self-triggered”—usually in winter storms with strong winds. Lightning can also be triggered by aircraft flying through strong electric fields. If the plane is below the cloud, then a CG flash could result.

In the most common type of cloud-to-ground lightning (CG), a channel of negative charge, called a stepped leader, will zigzag downward in roughly 50-yard segments in a forked pattern. This stepped leader is invisible to the human eye, and shoots to the ground in less time than it takes to blink. As it nears the ground, the negatively charged stepped leader causes streamer channels of positive charge to reach upward, normally from taller objects in the area, such as a tree, house, or telephone pole. When the oppositely-charged leader and streamer connect, a powerful electrical current begins flowing.

This return stroke current of bright luminosity travels about 60,000 miles per second back towards the cloud. A negative CG flash consists of one or perhaps as many as 20 return strokes. We see lightning flicker when the process rapidly repeats itself several times along the same path. The actual diameter of the lightning channel current is one to two inches, surrounded by a region of charged particles.
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Lots more information, pictures, and maps at this below link that runs our hemisphere's major lightning detection equipment.

https://www.vaisala.com/sites/defau...-Annual-Lightning-Report-2020-B212260EN-A.pdf

More on our US lightning detectors:

Lightning Detection

 

[hawkdon]

Nice info there...when I was a kidling I would see lightning
from the Ground UP into the clouds, from maybe mile or two
away, in the farm fields that surrounded me...very surprising....

 

[David777]

Recent lightning fatality in Colorado include a rancher and 34 of his cattle. Almost all deaths in California are at higher Sierra Nevada elevations that like in the Rockies, can have truly frightening lightning storms. The reason there are many more deaths in states like Florida or Texas versus California's High Sierra, is not because the storms are necessarily more dangerous or violent but rather because relatively few people are ever outside in those alpine mountains versus the millions in those other states at lower elevations like out at golf courses.

Jackson County rancher killed by lightning strike



Here is mr dave in August 2017 at a John Muir Wilderness camp spot at over 10k feet after a violent lightning hail thunderstorm left the ground covered white. The white in the background is still melting snow.



Next morning drying gear in the Sun.



Story:

...Well it began to rain with a few of those large single drops that make noticeable splatting sound. And then a moderate rain of increasing intensity as thunder became louder. About 1:30pm intense terrifying lightning and thunder were right on top of me as I was glad that I'd moved my camp spot. Loud pea sized hail began pummeling my tent and quickly reached the epic intensity of the storm three of us endured on July 8, 2015 but without snow of that storm.

Very soon I went into max emergency mode as falling gravity accelerated hail began pounding water through pin holes and water resistant material even strong rain would not have. Additionally temperatures dropped with so much ice and cool water vapor in the air causing considerable condensation to form on the inside layer of my tent fly that the impacting hail would then blast off as mist.

So everything inside the tent was becoming wet from mist. I used my day pack rain cover and rain shell to protect the top of my lower Marmot Pinnacle sleeping bag. Hail bouncing and rolling off the wet sagging inward tent walls was piling up at the base of the tent tub floor sides with water now draining beneath the tent and at my foot end some had found a pin hole to start wicking through.

I bring 2 long sleeve cotton and one short sleeve cotton t-shirts on trips. The latter became my tent mop as every few minutes I would bend over to reach the far end of the tent and sop up a new puddle. With the (Big Agnes) UL1, the inside roof of the inner tent is bug mesh so drips from the rain fly first splash against that.

Actually water was not dripping but spraying down with force from impacts on the top seam. I hoisted the t-shirt up right against the mesh trying to block the splashing. Hail pounding against the tent and outside landscape was at a loud roar only exceeded by thunderous claps every few seconds. My hand became icy cold and tired from stretching upward as the t-shirt was soon so wet it could not soak up anything more.

But the hail storm went on and on as did the lightning and thunder. The upper inner waterproof walls of my tub floor below the mesh was increasingly dripping water down getting items like my sleeping bag wet. I used my large cotton handkerchief to soak some of that up but the UL1 is so narrow that protecting gear that filled the floor space was futile. I wondered if this was going to be one of those nightmare crest storm scenarios where a really big thunderhead sits atop a peak and does not move, just dumping and dumping?

Looking outside beneath the vestibule, I could see a few inches deep of white and began wondering about hail avalanches since the slope directly above my position snow avalanched during winters. After a half hour as a helpless mortal blob of protoplasm, I as a religious person blurted out loud to God in essence that ok yeah You are in control and I am at your mercy. About 5 minutes later it eased up and over the next hour and one half kept raining with occasionally modest hail and lightning thunder but never as intense as that first half hour.

I humbly lived through it but could easily imagine not surviving due to hypothermia if such a storm had kept pounding down soaking my sleeping bag and clothing. Over four plus decades I have experienced many thunderstorms and together with the 2015 storm, I can say to others that unless one is in a heavy bombproof 4 season winter tent, that you could some day be tested by a terrifying summer storm as they do occur.

By 4:30pm the final sprinkling rains stopped that gave me a chance before nightfall to do what I could with my gear. After putting on all my warm clothes and sopping up excess water on my inner tent walls, I went outside finding a solid 4 inches of pea sized hail covering landscapes though not like snow since hail tends to bounce off solid objects thus rocky areas were just wet...

Hail had piled up along the sides of my tent about 8 inches so spent awhile digging all those white marbles off the tent walls as best I could while wearing some thin Gortex gloves. A pot and plastic cup were about 3/4 full of hail and water while a number of small cooking items were somewhere buried beneath the white. My pack with its rain cover was safely below the overhang of a large boulder at camp.

 

[His Dudeness]

I've lived on my property since 2009. We have had 3 lightning strikes in the front yard. The previous owner did not bury the telephone line or well piping very deep. So, we've had 3 instances where phones and DSL routers were melted from strikes. The last one actually caught the phone base on fire. I now have everything running through surge protectors.

 

[papa tiger]

I saw a small palm outside Miami, fla. several years Ago. Trunk staked with cable
to protect it from wind and the top burnt out of it.

A Hickory about 100’ from our lake home was hit and killed. Cut it and removed the mess.

 

[David777]

I've lived on my property since 2009. We have had 3 lightning strikes in the front yard. The previous owner did not bury the telephone line or well piping very deep. So, we've had 3 instances where phones and DSL routers were melted from strikes. The last one actually caught the phone base on fire. I now have everything running through surge protectors.

Yes telephone lines are among the most often lightning struck objects along with trees because they are in physical contact with relatively low resistance pathways to general area utility ground. Most ground strikes are between positive zigzagging leaders from moving with the wind clouds and most negative ionized ground elements. The negative ground elements are not generally negative but rather neutral.

But because they are low resistance connected to otherwise negative areas even at a distance, when a positive leaders hangs closer to the ground, it draws those negative charges to such objects. But as such cloud leaders move away due to wind moving the cloud above, the ground areas with most positive charge moves along the ground likewise. That is what causes mountain climbers to sometimes feel tingly static that is a sign of an imminent lightning strike.

My last 8 years of electronic hardware work was for a major business corporation of VOIP telephone systems. I was the sole person testing and repairing what are called VOIP media gateway switch circuit boards that lightning on telephone lines often ended up at causing all manner of usually unrepairable burned lightning damaged equipment.

 

[Murrmurr]

Me and my kids lived in an old mobile home out in the western Nevada desert for a couple years, and one afternoon we were all laying on the floor watching a thunder storm through the sliding glass door when a mighty streak of lightening hit the ground just about 300ft away from our front deck. It made a deep, kind of muted whoomp! sound when it hit the sand, and momentarily raised about a 2ft-wide mound of earth a good 10" high.

But equally awesome, we felt that strike reverberate under our bellies, up through the floor, and we all looked at each other and said "Whooaa."