Haze gray and underway is a United States Navy saying that refers to surface ships in arduous duty at sea, in contrast to submarines or naval units in ceremonial roles or in port. It is a term of tribal pride and identification, e.g. surface ship crew use it to distinguish themselves from submarine crew.
Most tornadoes form beneath the cumulonimbus clouds of thunderstorms, quite often the large, long-lasting thunderstorms called supercells. Cumulonimbus clouds can be very tall, having bases in the lower troposphere and strong updrafts that carry moisture into middle and upper levels of the troposphere.