3 ms·

OK. But what is happening in the video when that happens? Is the lightning striking right in front of the camera? I thought we were just watching the somewhat f

• kzrdude 4y ago
  The precursors and the big flash have very different brightness, that's what it looks like.
• mannykannot 4y ago
  The bright, branching, jagged lines reaching up and down are not the lightning bolts themselves, but stepped leaders (down) and streamers (up). They are ionized channels of air, and they grow at their tips because that is where the electric field strength is highest (it is analogous to crack propagation in solid materials, where the stress is concentrated at the tip.) At this point, there is still an insulating gap between them, and the only current in these channels is due to the rate at which this ionization progresses. Once the leaders connect the cloud to the ground, however, there is essentially a short-circuit between them, and a much greater current can flow - the return stroke. It is usually this you see when you see a lightning stroke, and it is far brighter than the leaders and streamers. The sensitivity (aperture?) of this camera is set to capture the leaders, and is overwhelmed by the brightness of the return stroke. In this case, there seem to have been two bolts in quick succession, with the second hitting a nearby building on the right. https://www.weather.gov/safety/lightning-science-initiation-leaders https://www.weather.gov/safety/lightning-science-initiation-... https://www.weather.gov/safety/lightning-science-connection-ground https://www.weather.gov/safety/lightning-science-connection-... https://www.weather.gov/safety/lightning-science-return-stroke https://www.weather.gov/safety/lightning-science-return-stro... In these videos, you can see the ionization occurring at the tips of the leaders (play the first at 0.25 speed): https://youtu.be/qQKhIK4pvYo?t=306 https://youtu.be/qQKhIK4pvYo?t=306 https://www.youtube.com/watch?v=JVXy-ZqqZ-g https://www.youtube.com/watch?v=JVXy-ZqqZ-g