What level does lightning start at in minecraft?

How high does lightning spawn? My current abode sits above the clouds and I'm wondering if it can be struck by lightning. Is there some level lightning appears or does it come from the "top" of the sky?

It comes down the "top" of the map, I have been struck by lightning at the top of a tall tower before!

I'm not sure whether a bedrock level pit would allow you to survive, going to test this now

EDIT:

I was in the bottom of my pit mine today and got hit killed by lightning, then immediately thought of this post. -_-

127, and it vertically strikes at the first solid block below. This logic is unrelated to how it is rendered.