Lightning strike over observatory.

[Astroman (Andrew Wall)]

Awesome strike Justin!

[tilbrook@rbe.ne (Justin Tilbrook)]

Hi,

Thanks Andrew, was that your video of funnel cloud on channel nine news last night?

I've been admiring your work, you're certainly dedicated to it.
Worked out how far away that strike was, with the speed of sound through air at a temp of 20 degree's celcius being 331.5 mps, I timed the flash to the lightning strike to to the thunder of an an average of three timings, of 4.9 seconds.

Comes out at approx 1.6 kms away.

That's close enough!

Cheers,
Justin.

[Pi]

That is some fantastic fortune to be standing right in that spot with the camera rolling at that exact time! Awesome stuff

Originally Posted by gregbradley

Fantastic lighting shots.

Does anyone know why lightning is jagged and not a smooth arc or straight line?

Greg.

I'd say it is because current (flow of electrons) likes to flow through the path of least resistance. The resistance of the atmosphere is going to be determined by factors such as moisture and impurities present at a specific location and therefore won't be constant. The jagged arch is due to these variations in resistance from the static charge build up to earth.

[Astroman (Andrew Wall)]

Originally Posted by tilbrook@rbe.ne

Hi,

Thanks Andrew, was that your video of funnel cloud on channel nine news last night?

I've been admiring your work, you're certainly dedicated to it.
Worked out how far away that strike was, with the speed of sound through air at a temp of 20 degree's celcius being 331.5 mps, I timed the flash to the lightning strike to to the thunder of an an average of three timings, of 4.9 seconds.

Comes out at approx 1.6 kms away.

That's close enough!

Cheers,
Justin.

Yes Justin, that is my Funnel Footage that was shown. Unfortunately for some reason my email forwarding for youtube didn't work so I missed Channel 9's email about it... I love Chasing Thunderstorms and love the thrill of capturing something like this.

1.6km thats not too bad then, it's a good distance without being too scary... some may disagree. Closest I have been was 3m, luckily I was in my car, closest outside the car, 50ft...

Enough to make your hair stand on end literally.

Do you have available the video? I have a few friends who would LOVE to see the footage with the thunder....

[tilbrook@rbe.ne (Justin Tilbrook)]

Hi, Andrew.

50ft !!! too close for me.
Yes i have the video, I"ll pm it later.
Just trying to cut the video and slow it down. There seems to be three parts to the strike, the initial strike, then a bright single half length and finally a full single thats fainter that seems to go back up into the clouds???

Have you witnessed this before?

Cheers,

Justin.

[Astroman (Andrew Wall)]

You should have different phases of the strike, happens quite quickly sometimes but often it's not just one strike you see, it's multiple. You should see something like a bright strike, or return stroke, which happens when the stepped leader from the lightning strike makes contact with the streamer from the ground. then after the initial contact things calm down a bit and you get the single looking channel. the half channel could be internal lens reflection also, due to the brightness of the strike. If you send me the video I'd be able to tell you.

Would you give me permission to show it to other people also? with proper credits of course.

[bartman (Bart)]

Originally Posted by gregbradley

Does anyone know why lightning is jagged and not a smooth arc or straight line?
Greg.

Originally Posted by Pi

I'd say it is because current (flow of electrons) likes to flow through the path of least resistance. The resistance of the atmosphere is going to be determined by factors such as moisture and impurities present at a specific location and therefore won't be constant. The jagged arch is due to these variations in resistance from the static charge build up to earth.

Greg/Pi,
Hhehehe I saw the question and thought the same thing as Pi. Path of least resistance......but could not quantify it!
Thanks Pi for the explanation ( I did ponder the atmospheric irregularities as a possibility, but wasn't sure )
Cheers
Bartman

[tilbrook@rbe.ne (Justin Tilbrook)]

No problem Andrew.

Sent you a PM can you reply to it so I can send the video.

Cheers,
Justin

[Astroman (Andrew Wall)]

Originally Posted by tilbrook@rbe.ne

No problem Andrew.

Sent you a PM can you reply to it so I can send the video.

Cheers,
Justin

Okay haven't got the PM yet... or am I a bit early

[RosieA (Rosie)]

Fabulous

[ChrisM]

Fantastic capture Justin. The shot with the many forks looks surreal.

I've wondered a few times whether a tall conducting telescope pier coupled with a non-conducting dome (eg. fibreglass) would ever attract lightning and pose a hazard to the observatory equipment. If I know that a storm is coming I usually unplug the internet connection to the obs and turn off the main switch on the sub-board.

Chris

[tilbrook@rbe.ne (Justin Tilbrook)]

Hi,

Thanks for the comments.
The image is a bit deceptive, the strike was 1.6 kms away. I timed it off the video.
Yeh, I don't know whether a fibre glass dome would be be any protection? I suppose someone on this forum would know. As for my dome, it's all metal and would imagine it would damage the scope and sundry items if it were hit.
Fortunately my power source for the observatory can be unplugged in my garage.

Cheers,

Justin.