Hi Tim - Really nice sky shot with nice cloud formations. I do think there is a bit too much dark foreground in your composition. You might try croping the sky just above the projecting branch near the center of your shot and croping 2/3rds of the dark forground. You would then have a panorama shot with very little area without interesting details. These shots are tough to get and you have a nice capture here..
The colours are beautiful and I love the silhouette & cloud formations....I would have to agree about cropping a bit off the bottom though....but still a beautiful shot.