Lightning Leaders?

Simon Gruber Says

I was looking at a video I recorded in June of last year because I remember noticing some unusual sparks in it. The storm showed signs of rotation and had very heavy precipitation but produced no lightning that I saw. These "sparks" I noticed happened on two occasions in the video, one appears vertical from the top of the video and the other streak vertically from left to right. They're extremely brief, lasting only a fraction of a second and I've taken screenshot and highlighted the areas below of where to watch to see them.

Here's the video itself, turn the quality to HD

First one :- Occurs at 2:00 in the video in the marked area. The grey streak is the best screenshot I could get.



Second one :- Occurs at 3:23. The marked grey dot is all I could capture and this one moves from left to right.



Anybody got any idea what these sparks are? It's not lightning as it produced no thunder and appears to be not bright enough and the second one appears to happen away from the clouds. The only thing I can think of is a lightning leader that somehow dosen't result in a strike but I don't know if that's possible even

This is how it looked on the Met.ie radar.



And this is an image of the storm itself I took from Howth Summit

riffmongous

Any sort of lightning discharge would result in a radio signal being made I think, you should look on one of the European radio based lightning detection websites. Let me see if I can find a link for you, I forgot the name of it

Edit: this is the one we have over here, perhaps you can find a link to an Irish based one
http://www.aldis.at/

Simon Gruber Says

riffmongous wrote: »

Any sort of lightning discharge would result in a radio signal being made I think, you should look on one of the European radio based lightning detection websites. Let me see if I can find a link for you, I forgot the name of it

Edit: this is the one we have over here, perhaps you can find a link to an Irish based one
http://www.aldis.at/

Here's the MET.ie one for that day, http://www.met.ie/climate/lightning.asp?ReportDate=18%2F06%2F2012

The strikes recorded are a good bit north of where I was, but as I said there was no thunder, also I only noticed them when watching the video, not while I was recording it

riffmongous

Simon Gruber Says wrote: »

Here's the MET.ie one for that day, http://www.met.ie/climate/lightning.asp?ReportDate=18%2F06%2F2012

The strikes recorded are a good bit north of where I was, but as I said there was no thunder, also I only noticed them when watching the video, not while I was recording it

Where were you exactly and when? Seems afternoon around Howth anyway, then I wouldn't be too concerned about the location, the spatial resolution on this detection method might not be too good. There was definitely lightning in that region though around that time judging by the image.

I am not sure about the exact physics of thunder but I do seem to recall often seeing lightning that resulted in no audible thunder, if what you saw was lightning it looks pretty weak and perhaps any thunder generated was too weak for you to hear.

Simon Gruber Says

riffmongous wrote: »

Where were you exactly and when? Seems afternoon around Howth anyway, then I wouldn't be too concerned about the location, the spatial resolution on this detection method might not be too good. There was definitely lightning in that region though around that time judging by the image.

I am not sure about the exact physics of thunder but I do seem to recall often seeing lightning that resulted in no audible thunder, if what you saw was lightning it looks pretty weak and perhaps any thunder generated was too weak for you to hear.

I was about 2 or 3 miles south of Howth at between 6 and 6:30pm. The lightning shown on the detector was caused by a storm that passed about an hour before this over Swords and produced lightning strikes there. I followed the storm until it moved out to sea. I saw no lightning in the whole time, but I have no idea about weak lightning that isn't as noticeable/dosen't produce thunder.