“积雨云云的顶部通常约40000英尺,高度可以达到超过60000英尺,这将是可见的245或300英里的距离,分别。”June 25, 2015 My crazy cousin said that at, say, 300 miles, said NOT could see this cloud formation - maybe just the top of it - because of the earth curvature ( distance: 300 miles - curve 11.3618 miles below sight (also 59990.14 feet). I am certain that he is wrong. But it is logical and the earth curvature calculation is legitimate.