Clouds Today

I couldn't help but notice the clouds this afternoon while I was standing next the pool coaching swim team. We read in class that contrails, the clouds formed by airplanes disturbing the air, under the right conditions, can turn into large stratus clouds. I watched it before my eyes this afternoon. There were many persistent contrails, over time some of them were getting wider and becoming stratus clouds. Some cumulus clouds were also beginning to form. It must have been just the right conditions for clouds to form and expand. I wonder how often the conditions are right for contrails to expand into stratus clouds.