Dan Robinson
Enduring 30 minutes of standing outside in a thunderstorm core paid off this evening. I captured four out of seven strikes to the WVAH tower, up close and personal with all three video cameras, with wide, telephoto and extreme telephoto views. Heavy rain, strong winds and low clouds enveloping the tower prevented capture of the first three strikes.
More frame grabs and a video clip are here:
http://wvlightning.com/july42006.shtml
The most remarkable event tonight was the observation and capture on video of an upward 'leader' or 'streamer' off of the antenna tip. This particular event was not a 'ghost image' or 'false leader' otherwise common with videotaped strikes. The leader occured in conjunction and simultaneously with an in-cloud flash above the tower. A lightning leader began propagating upward from the antenna tip, but did not complete a cloud connection to a full discharge - rather ending abruptly in mid-air approximately 200-300 feet above the tower. The video image supports this, as well as the thunder observed and audibly recorded by the cameras. The noise consisted of a short 'sizzling' sound that resembled the start of a normal peal of thunder, but stopping abruptly after a split second due to the fact that the leader channel was only 200-300 feet in length.
Camera #3 was shooting wide and captured the entire leader channel (contrast enhanced):
Camera #2 was zoomed and captured the lower section of the channel:
Note that a 'ghost image' channel would be shifted downward on the screen (see http://wvlightning.com/videoghost.shtml). This channel is in the correct position on the video image, its lower terminus correlating to the antenna tip. A 'ghost leader' would also have preceded a full discharge, in this case which there was none.
Unfortunately I was changing the tape on camera #1 and did not get the extreme telephoto view of this leader.
The following is the video from cameras #2 and #3. Listen closely for the thunder as described above (a short sizzling sound).
http://wvlightning.com/2006/july4leader.wmv
Another item of interest is the capture by camera #2 of the very first stages of upward leader initiation on a frame preceding a full discharge. The leader channel on this frame is no more than 5 to 10 feet long: