Where did that come from?

I find it quite amazing sometimes how clouds bubble up out of nowhere at short notice. I had left home to clear moonlit skies, with only the hint of a cloud on the horizon to the east.

Then, less than 20 minutes or so later, this is the scene that was before me. THe clouds were banked up across the horizon in front of the rising sun and these dark clouds were above. In the end you work with what youve got but I must admit I was expecting a much more colourful sunrise.