why does (part of) lightning strike upwards?
Apparently shortly before lightning strikes, there are positively charged streamers rising from the ground that create a path for the lightning to follow.
What I don't get is why/how these streamers form in the first place? What causes the electrons in that area (rather than another area 30 feet to one side) to get sucked away?
Also, how the heck do they detect these streamers? are they visible? if they are visible, has anybody ever managed to get a picture of one?
note: I've read the wikipedia entry and understand how a negatively charged cloud formation will cause the ground to become positively charged (like repels like).