Ok, before I say anything, I'm NO pro - just a keen hobbyist.
The tree, the dark clouds, the forground rocks and rocky shoreline, they are nice elements and subjects, but I feel the line of distant trees of another shoreline cutting across the whole composition, ruined it all.
Also, I would want to look for alternative angles, recompositions, and there is some over-exposures on upper left corner - bright portion of sky.
On the whole, the picture is (for lack of a kinder expression) rather stiff..
At the onset, I saw the tree first, then I was disrupted by the horizon of trees cutting across it. Personally, I avoid putting things smack in the center.. Unless its some pretty girl...hehehehe...