On a Delta flight from Denver to Orlando beautiful Skies above the clouds noticed that off in the distance ( probably 5 miles) a very dark "rain" cloud came up through the clouds possibly the size of a football I noticed it was holding shape and not breaking apart it is still eye level as it got closer I grabbed my phone turned it on which takes a min we still hadn't passed it I got several pics of it before we passed it that's when I realize it's changing positions up/down.i apologize my phones cam takes horrible pic but you can see something.