Every rule or guideline in photography has an exception. A lot of what we like in our images is subjective, although composition and lighting principles give us a common framework to critique our work as well as the work of others. One important aspect of an image is the quality of light.
Tornado warnings. 60 mile-per-hour winds. Rain. Lightning. Generally, when you hear these weather alerts, the last thing you are thinking about is going out to shoot. But time and again I have learned the hard way, that if you don't give it a try, you may miss a great shot.