Lightning is generally something that is very brief, a strokes lasting a few milliseconds, might be a number of those in rapid succession yielding a lightning strike lasting several hundred milliseconds, usually.
I witnessed something that was quite out of the ordinary. Those of you who both live in the Seattle area and have lived or traveled elsewhere, know that Seattle area lightning storms are normally quite wimpy. Usually, we'll get a stroke or two and then it will start pouring down rain and we're done. Occasionally, we'll get a more intense storm where it continues after it rains for up to half an hour or so, but those are rare. We'll also get summer "heat lightning" on occasion, generally during solar peaks, again relatively rare.
During my Jr. high and high school years, I ran a bootleg radio station and so did some friends. One of those friends operated both a shortwave and AM station out of his home in the Wedgewood area. I lived up on Mapleleaf ridge. We all participated in each others stations to some degree.
I had gone over to my friends in Wedgewood, and on the way back a storm had come in. It was nasty as Seattle storms go, clouds were so thick it was almost like night, street lights had all turned on it was so dark. It was so dark in fact that headlights were needed and visible on the road. It was an absolute torrential downpour with intense lightning, an intensity like I've never seen here before or sense (though common place in some other places I've been).
Coming back from Wedgewood, I crossed Lake City way at 85th Street NE, drove up the hill to 17th Ave and turned left (north) on 17th. Either crossing 86th or 88th Street, I don't remember which but it was one of those two, as I looked right, towards Lake Washington, there was a strike that appeared to be over the lake. Now, I should qualify that, I can see from there, the hill on this side (west) of the lake and the hill on the far side (east of the lake), but I can't see the east slope of the west hill, so I can't see that the lightning actually hit the lake, I can only tell it was in front of the far hill and behind the near hill, but could have struck the east side of the west hill.
Whatever it hit, it was a massive bright stroke and it continued as I passed through the intersection, so long, that I stopped the car, put it in reverse, and backed up into the intersection again before it extinguished. I would estimate 15-20 seconds. By that time it had changed from it's initial blue-white to a deep crimson red, much like the color you get when you put strontium-chloride in a flame. I have never seen anything like that before or sense.
That happened 32 years ago. I've asked around a lot since then, dug around the Internet, and never have found another account of an incident like that, but I did find one person who had a possible explanation. He said that under the right circumstances, after the initial charge as that part of a cloud approaches ground potential, it increases the potential between it and the surrounding regions, which can then start feeding charge to it and that area can just expand out. Now it was an extremely thick cloud cover, so perhaps that happened. The red color he thought might have been the result of nitrous oxides formed during the long stroke. At any rate; it's just speculation on what the actual cause was but it was exciting. When something powerful and completely out of the ordinary like that happens, well all sorts of ominous thoughts came to mind.