I found this tidbit from a Harold Humes, a quite bizarre fellow. >"The story in a nutshell is this: when lenticular clouds were first sighted in the 50's, the problem nobody could get around was the fact that they were able to hold their position against prevailing winds. Now, a normal cloud moves with the wind because it's part of the wind. In other words, a cloud is water vapor, coming out of a solution. It's condensing to make a cloud. Water vapor is one of the gases that make air. When water vapor comes out of the air to make a cloud, the cloud moves along normally. It's perfectly logical, common sense tells you that. > The puzzling thing about lenticular clouds--which are water clouds too--the thing that puzzled everyone who looked at them, from airline pilots to meteorologists, was the fact that they could hold their position against prevailing winds. For example, you'd see a lenticular cloud sitting over the Charles River and there might be a prevailing breeze of 25 knots blowing but the cloud would stay in exactly the same position. The wind goes on but the cloud stays put. That presented a lot of problems, because if the cloud's not moving with the wind, that suggests it's not an ordinary meteorological phenomenon. There's something going on that's new. Definitely novel. It suggests the possibility that the cloud is not a meteorological phenomenon but in fact an ethereal phenomenon."