Great looking sky! The problem is that the bottom part of the image is so dark. It seems like it is swallowing the good of the sky. Needed more detail or a different perspective.
Pretty sky, but if the tree line was closer so that the branches were more define, I think the photo would be stronger. Nice use of negative space anyhow.
The lower part of the frame is WAY too dark. The sky looks like it may have made for a good potential sunset, but this shot doesn't say "night" to me. That very well could be the moon behind the hill, but it isn't obvious to me.