Here is some of the science behind all of that. For the purpose of this blog I am concerned only with cloud to earth electrical activity. You do not need a solid understanding of electromagnetism or thermodynamics to read this post.
Much research is still needed to nail every thing down as fully understood. However, what I write here is fine for us mere mortals.
A large dark grey cloud had just rolled in overhead. A charge separation had taken place within the cloud aggregating the negative charges at the bottom of the cloud. These charges induced a shift in charge placement within the earth's surface, placing the positive charges (positrons) near the earth's surface under the cloud.
A positron streamer found its way up me. Likely the trees, and the building in the area were sporting streamers, as well. My streamer is what caused the tingling sensation in my arms and hands.
Now the thunder cloud sends out negatively charged leaders. These can strike downward towards a streamer. The air contains an uneven distribution of impurities creating paths of varying resistance to electrical current. The leader will follow the path of least resistance creating the branched step leaders of what we think of as lightning. When leader connects with streamer a plasma channel is formed. Keep in mind plasma is what constitutes stars. Owing to resistivity considerations the leader may ignore the forty foot tree's streamer in favor of the tiny human being running up the muddy dirt road.
Once the plasma channel is formed a blinding flash occurs as positrons flow from the ground up to the cloud to equalize the charges. The temperature is close to that of the sun's surface. A shock wave extends from the lightning strike outward knocking anyone in the vicinity out cold. To complicate matters a lightning strike sends out an electromagnetic pulse (EMP) scrambling electronic equipment. Sometimes shutting the equipment off completely before restarting will restore proper hardware state, if nothing is completely fried.
All ended well for me, but not so well for some neighbors who lost routers and switches.