How far away can you actually observe lightning?

[East_England_Stormchaser91]

Thought I would start a thread regarding the furthest distance lightning can really be observed from.

Ive read a few times this past summer, during the storms of this year in particular including myself of observing and witnessing the flickering of lightning from well in excess of 100 miles away, perhaps nearing or exceeding 150 miles! 

I myself can certainly say that up here on the lincs/Cambs border have witnessed regular flashes from storms as far away as Wiltshire and Dorset, and more recently as far as the IOW! 

Someone on another forum claimed that they had witnessed from Suffolk flashes from storms as far away as the Dutch/German border! And flashes over Belgium from Northamptonshire!!! 

Any takes on this folks? 

[Abyss]

Google informs me up to 100 miles away and it's difficult to hear thunder beyond 15 miles. Living near the Atlantic I have often seen lightning at night when it's clear and heard no Thunder. My Granny used to call it openings ha

[East_England_Stormchaser91]

Yeah I've read 'up to' 100 miles away on google. But my own eyes have told me that it is definitely further than that! The Isle of Wight from here is over 150 miles as the crow flies! Maybe because of the flat landscape of the fens, it gives massive unimpeded views around here. 

[Methuselah]

1 minute ago, East_England_Stormchaser91 said:

Yeah I've read 'up to' 100 miles away on google. But my own eyes have told me that it is definitely further than that! The Isle of Wight from here is over 150 miles as the crow flies! Maybe because of the flat landscape of the fens, it gives massive unimpeded views around here. 

I tend to agree, EES. I'm sure that (unless my eyes were deceiving me) I could see lightning in MK, all the way from over here...The air was exceptionally clear at the time, mind you.

[Nick L]

I've seen it from the best part of 100 miles away in the states of a night.

[NO LONGER POSTING]

I once saw lightning in Bristol from a storm and I was in West London... 

[hillbilly]

From my old house I could see Humber bridge on a chrystal clear day,that is over 70 miles away so I do not see why you cannot see lightening at night at conciderably further !

 

[Battlemage]

I know this is an older thread, but I thought I'd give a solid theoretical answer to this question based on some over-estimating assumptions.

 

Given the curvature of the earth, you can use geometry to find the maximum distance for which you could see lightning. We can use the following formula:

d = (2RH + H2 - 2Rh - h2)1/2

where H is the height of the clouds, d is the distance, h is your height, and R is the distance to the center of the earth. This formula makes the assumption that the earth can be approximated as a sphere, and it assumes that the angle between your line of sight to the lightning and the line from the center of the earth through your body is 90 degrees (a reasonable assumption since the earth is approximately flat over short distances). My use of the formula assumes the topmost cloud layer is 49,000 feet high (based on wikipedia's info on the height of clouds from which lightning originates), the distance to the center of the earth is about 4000 miles and the height of the observer is 6 feet. Using those numbers, the approximate theoretical furthest distance you can see lightning from is:

 

d = (2*4000 miles*49,000ft +  (49,000 ft)2 -(2*4000 miles*6ft) - (6 ft)2)1/2 ≈ 273 miles.

 

So there you have it folks ;). In theory you could see lightning from a lot further away than what everyone was guessing. Of course, these assumptions make this the MAXIMUM POSSIBLE that you'd be able to see just the top part of it, and that's assuming that you even see it at it's origin point. So this is probably an overestimation. But at least we can be confident that the limit is about from this distance.

 

*as far as accuracy for these estimations, before I did this I also did a more simplified calculation in which your height was zero, which gave the formula d = (2RH + H2)1/2. This formula gave 272 miles, so you can see the other terms that depend upon your own height don't really matter.

 

Regardless, this is an estimation, but you can see that it's on the order of 2.5 to 3.5 hundred miles. If you use the law of cosines and solve for that distance, the angle differing from 90 degrees by 1 degree or so makes a difference, but really, 90 degrees is a solid estimation given the large distance, since the replies in this thread give values ranging of around 150 miles, which would correspond to an angle of about 92 degrees rather than 90. So I think an assumption of 90 degrees gives a reasonable guess for the MAXIMUM distance you could see.

[Interitus]

Good reply, but just a couple of thoughts. The height of cumulonimbus clouds are restricted by the tropopause, where the cloud spreads out forming the characteristic anvil shape. There can be a degree of overshoot, but cumulonimbus don't reach 49,000 feet over the UK so lowering the estimated distance. However on the other hand, at night in particular, high cloud layers can reflect the light from the lightning which may otherwise be over the horizon.

[SummerShower]

Know this is an old thread but yesterday evening about 10pm to the se from Basingstoke I observed lightning.  Nothing unusual there but the nearest strikes at the time were off the east Sussex coast.  As the crow flies this is about 100 miles away.  I dont believe I have seen it anywhere near this far before and didnt know it was possible before reading this thread.  Probably the sky being deeply clear helped on this occasion..

[Sunny76]

Probably from about 10-20 miles away, especially if your in the city. 
 

If based in the countryside, you can probably see lightning from about 40 miles away.

I remember we could see fork lightning out in the Mediterranean, while on holiday in Murcia. My guess is, that was about 30-40 miles away, as we couldn’t hear the thunder. 

Edited August 17, 2020 by Sunny76

[cheeky_monkey]

i would concur on 100 miles at night..have seen lighting from storms that have been happening in Red deer or south of there even.. and that's over 100 miles away due south

[Earthshine]

I'm actually doing a research project which involves the range of electromagnetic radiation.

The range of a ray of light depends on numerous factors, including the height of the ray source, the distance to the ray source and the refractivity structure of the atmosphere.  Atmospheric ducting (which can occur when there is an inversion layer associated with a negative lapse rate) can increase the range of light rays as they can become 'trapped' inside the atmospheric duct, which can act as a wave guide.

Theoretically, the ray of light can be guided over the curvature of the Earth along the extent of the inversion layer.  Atmospheric refraction increases the distance to the apparent horizon and allows light sources that are below the geometric horizon to become visible.

Figure is from "Evaluation of Mobile GSM Performance under Different Atmospheric 
Propagation Models". Qaysar S.Mahdi & Idris H.Salih. December 2017. Eurasian Journal of Science & Engineering. Vol. 3. P. 153

[Weather-history]

I've caught night lightning on my timelapses from storms off the Cumbrian coast as can be seen near the end of this time lapse about 70 miles away

 

 

[lazy_rob]

Glad I found this question and people's thoughts - couldn't quite believe my eyes just now.

On holiday near Great Yarmouth and have just been looking out to sea (10pm) on a crystal clear night and can see lots of what can only be lightning strikes right across the horizon in the very far distance - quite a light show.

Checking a lightning strike radar, the nearest storm is north and south of Amsterdam about 130 miles away over the North sea - Wikipedia was suggesting that 100 miles was the upper limit but my experience (along with others on here) seems to suggest that it is significantly more than that.

Tried to get a picture/video, but only had my phone and it really didn't register, but impressive to the eye nevertheless.

[Zak M]

I have observed lightning from over 150 miles away before.

 

[38.7°C]

Are lightning maps accurate though? The maps could show a lightning strike 150 miles away but when its actually about 50 miles away. A bit like pinpointing your location where your logged in on facebook for example when you check your logged in status it often shows your logged in places about 100 miles away....Dont lightning strikes use the same GPS signals to determine where they happened ?

[East_England_Stormchaser91]

On 20/08/2020 at 23:26, Zak M said:

I have observed lightning from over 150 miles away before.

 

Amazing video and great proof. Even more impressive with the Sandy Heath transmitter I’m assuming cross referencing the direction! 

Them ones between Holland and the Norfolk coast were touching on 200 miles I dare say just before dawn, nearly a month ago. 

[carinthian]

Just to confirm in my location on the borders of Salzburgerland/Carinthia, lightning can often been seen on clear nights over the Gulf of Trieste, Northern tip of Adriatic Sea about 140km away.I am fairly certain,I have also seen flashes from individually storms from as far away as Venice. Makes the world look small and awesome at the same time.

C

[fujita5]

Back in the late 1990s I remember one night I could see CONSTANT flashing that started to the SW and slowly spread through W and then to the NW, low in the sky.  There was a weather warning out for much of the south.

Turns out that the storms developed south of Southampton and tracked to Leicester that night.   The closest lightning would have been around 109 miles away in Oxford (where a tornado was reported and coincided with the strongest lightning), and up to 128 miles in Southampton.

[MP-R]

In March this year I could see lightning flickering away towards the Severn Estuary in line with Exmoor from the M4 between Membury and Swindon.

It did help that there was largely clear sky ahead of it.

[East_England_Stormchaser91]

On 13/09/2020 at 13:52, 38.7°C said:

Are lightning maps accurate though? The maps could show a lightning strike 150 miles away but when its actually about 50 miles away. A bit like pinpointing your location where your logged in on facebook for example when you check your logged in status it often shows your logged in places about 100 miles away....Dont lightning strikes use the same GPS signals to determine where they happened ?

Usually they are fairly accurate. I always check the radar for further back up of the strike displayed. 

[DogToffee]

The only time I recall seeing distant lightning was in the late 80s, driving out of Leeds towards the Pennines. The sky was flashing very regularly, but nothing ever came our way - I presume the storms were at least over Manchester way if not further. Being pre-internet and after the 9:30 weather forecast, I had no way of checking what was going on.