Great use of tonalities throughout the image. I believe I have seen that strucure before but I just can't place it. I am sure it was in a prior challenge but from a different angle. I would suggest burning the clouds to make it even "angrier". Ansel Adams was know for big, hunky, angry clouds. Great job!
Composition is very nice. Processing-wise, this is close, but not quite right for an AA tribute. The horizon line has a visible glow from processing and the blacks and whites are just a bit too solid to the point of detail loss. A more carefully reprocessed version would be a nice thing to see.