Your cloud and weather photos never cease to amaze me, wxnut. I like this one because you captured the texture of the big, very interesting, almost bubbling cloud in such a manner that it seems "solid", "touchable" and ... moving (like I was saying, it seems to be bubbling).
What more I like about this photo is the total reduction to 4 colours only (with their nuances, of course, but... you know!): the green of the grass and plants, the brown of the hug, the blue of the sky and the white (no colour, ok!) of the cloud.
Great one!