You gotta chatch a rainbow when you can, and this you did. IMO it is too bad mother nature was so stingy with color in the sky. The storm clouds give your picture a gloomy feel and I think to sell it would need more POP. The partial buildings on the left don't help either. 5
Wow, that rainbow looks pretty low. Are you rather high up or was it really that low? It's a very dark photo for a rainbow shot, but, who knows, for the right article or something this might be just what they need. I can't make up my mind if the horizon (grass) is a little tilted or not, so if it is, it's just a tiny bit. Other than that, technically a nice photo.
Beautiful rainbow. A tough contrast and you captured it well. Too bad the mountains are covered in the back. You might crop it up just a touch from the bottom.
It's not too often that one sees a rainbow as long as this. I saw some recently when I was in Hawaii but I don't think I had ever seen one before that. You've captured this one nicely.