Yup. When the ice crystals smash together in a cloud, it builds up friction. Makes top of cloud all positive, and bottom of cloud negative. As this builds up more and more to the point the negative at the bottom of the cloud has enough charge to be attracted to the positive of the earth. Then the magic happens. Leaders fly out from the cloud and make its way to the positive of the earth. Positive earth reaches up as the negative leader from the cloud reaches down. Until opposites connect. And boom. Strangely I hated storms as a kid. And then science took over. I'm absolutely fascinated by them these days lol Ice crystals bit, can often explain why hailstone often accompanies a storm....
The really big hail rise & fall a number of times, each cycle adds another layer of ice until they get too big & the updraught can no longer support them.
I'd be surprised if there wasn't any tornadic activity. There was certainly all the ingredients needed, without access to a detailed doppler radar its hard to say for certain. I witnessed before dark some rotation in the clouds, but on the radar I had access to it was hard to spot any hook signatures. I've struggled to find the heights of the clouds from last night. The amount of hail, and energy released would have been on par with some of the US super cells you witness on weather programmes.
The initial stroke is downward and is known as the leader stroke. If you are wearing rubber boots and get struck, you'll get a shock, but it won't kill you. The powerful stroke is the return stroke from the ground (positively charged) up into the cloud (negatively charged). The combination of leader and return stroke can happen several times in one lightning strike, which is why lightning flickers, which can best be seen in night storms. A good deal of lightning is cloud-to-cloud. I recall one storm which was timed at one flash of lightning per second for two hours (7200 strikes). It was formed on what was called an occluded front, which was higher than normal up in the sky, so none of the lightning strikes reached the ground, but you should of heard the angst of the pilots trying to land at the airport nearby.
Thundersnow! Ps this is an actual thing, not the name of a metal band.... I mean it probably is the name of a metal band, but I meant the snow storms forming in thundery conditions which are quite rare.