Lenticular
6,500 - 40,000 ft (2,000 - 12,000 m)
“Not everything that hovers is looking for a place to land”— Cloud observer wisdom
Lenticular clouds are the UFOs of the cloud world—smooth, lens-shaped formations that hover near mountains as if someone parked a flying saucer in the sky and forgot about it. They're probably responsible for more UFO sighting reports than any other natural phenomenon.
These stationary clouds form when moist air flows over a mountain and creates a standing wave on the lee side. The cloud forms at the crest of the wave and, unlike other clouds, stays in one place as air flows continuously through it—condensing on the upwind side, evaporating on the downwind side.
The smooth, layered appearance comes from stable atmospheric conditions that keep the wave pattern clean and regular. Sometimes you'll see a stack of lenticular clouds, one above another, like a pile of cosmic pancakes.
things worth knowing
- Lenticular clouds are technically classified as altocumulus lenticularis
- They can remain stationary for hours while air continuously flows through them
- Pilots avoid them because they indicate severe turbulence
- The highest recorded lenticular cloud reached 40,000 feet
- Mount Rainier and Mount Fuji are famous for their frequent lenticular displays
weather wisdom
Indicates strong winds aloft and wave action in the atmosphere; often precedes changing weather