When I have time to photograph, the weather and lighting conditions are not always cooperative. Last weekend was one such occasion where it was mostly cloudy but I was itching to do some shooting. So, I headed out to a local railroad that I knew was running steam and looked for compositions that would emphasize the surrounding environment instead of the sky. A little exploration led me to a nice s-curve that was oriented such that the trees formed a tunnel - light at both ends but fairly dark in the middle. A big black locomotive in the middle of a tunnel of trees is not exactly ideal from a lighting standpoint, but it does minimize the dull, gray sky that other compositions would have emphasized.
The original image was a bit flat but some small manipulations in Lightroom produced the image seen here. Next time it is cloudy and gray outside, don't let that keep you inside. There are plenty of compositions that can exploit nearly any lighting condition. As a photographer you just have to look a little harder on some days.