The in-laws just came back from a trip like that. The odds are about the same as dropping a thousand feet in a jet. It all follows the Binomial Theorem.
The greater chance is in the middle. The outer edges are where the rogue waves, and giant clear-air convection cells live.
Ah, writing and watching that gif gives me a headache, so I'll stop it here.
ps. I put some electrical tape on it. The BT is good for things that are a result of many influences. It's useless to try to predict, but there are lots of 'boundaries' on such things. If you are sitting on the deck at the cottage, looking over the lake, you will see many boat wakes. These wakes cross over each other, and sometimes produce really big waves that seem to march to their own drum. I always looked for these group waves when I was hauling the kids around on tubes. Great fun.