What an interesting picture.The coloring in your sky looks like a giant wave of water. I keep trying to wipe the bird off the screen. Wish there were just a touch more contrast in your sky. Very cool photo.
Ominous title; and ominous clouds to go with it. The repetition of the diagonals is quite effective - edge of building, line of cloud, angle of bird's wings. Enough grace, compositionally - enough real sense of finesse? I'm not quite convinced, I'm afraid.
I really like the color and the shape of that intense cloud, but I feel like something is still missing that could really grab my attention. Overall though a nice photo.