Changing weather is a great time to be on location. Don't wait for the weather to be perfect, you will only collect images that hundreds of other people have. Its almost a given that when the weather is in a state of flux, you can be assured you will come away with something unique.........if you are patient. One of the things I enjoy most is watching the light change as the suns rays pierce through holes and gaps in cloud formations. It is then that nature in its finest hour is displayed. Just be sure you know your camera well, otherwise the moment can be lost!