Is That A UFO?

When I saw my first picture of a lenticular cloud, I thought I was seeing a UFO. The disk like structure with the ominous shading, it looks like an object from an episode of the X-files. However, when I started learning more about these rare clouds, I couldn’t help but be fascinated. On a request from my dad, here is all about lenticular clouds!

Over Mt. Rainier, WA. Click in for more photos

A lenticular cloud or altocumulous lenticularis is a cloud formed by orographic lifting. Okay, orographic lifting… lets start there. This is a mechanism of forcing air due to things like mountains. When the wind blows an air mass near a mountain range or even tall buildings, that air is forced up in altitude. As the air rises in the atmosphere it is cooled and condensation generally occurs. This is how we get our orographic clouds! As the air rises and falls on the downwind side of the mountain, it creates eddies and the air is mixed.

A lenticular cloud is slightly different because these are formed from stable and moist air. This air is mechanically forced over the mountain range and then it is stretched to form a standing wave. Once condensation occurs, we have these special clouds. These clouds can be seen in many different ways as well! They can be just one sheet downstream of the mountain, they can be multiple layers looking like a stack of pancakes, and can even take on shapes like spheres or hearts. The important distinguishing feature about these clouds are their towering, layered structure and where they occur. These clouds also can form just downwind of the mountain range as well! They don’t have to be a cap over the peak, but they can be seen in rows or in a pattern downwind of the mountain. This is how I saw my first of these clouds. Driving home from North Dakota to Oregon, we were coming to the Rocky Mountains, through rows of standard cumulus clouds, there were these beautiful lenticular formations. Here is a picture of what I saw. Again, they aren’t always the same, but that is what makes them so beautiful and unique.

Photo I took at the downwind side of the Rocky Mts. You can see the lenticular cloud or “gravity wave” in the center of the screen.

So while they look a little “out of our world”, I don’t think that Fox Mulder would get very excited about these clouds.

Not quite what we are looking at
Not quite what we are looking at

Rebecca Anderson