You have a lot of patience! Great shot.
It is part patience, park luck and part effort.
The effort is getting there and getting up every day before dawn to see what happens.
The luck is in what the weather delivers as it is beyond the control of mere mortals.
The patience is accepting that every day is different and being content to wait for the golden moment.
On patience, I've seen comments on one of Ken Duncan's images where he says that he camped out for two weeks waiting for the weather to deliver "the shot." In a gallery in Sausalito, a large print of a Tetons scene had a caption saying the photographer had been camped out for a week before the shot printed was made. Maybe those comments are real, maybe they're made for commercial benefit but if my experience is anything to go by, unless you get very lucky, patience and persistence is required to get "the shot" in any natural landscape where clouds are involved.