Lenticular, or lee wave, clouds form downwind of an obstacle in the path of a strong air current. In the Boulder, Colorado, area, the obstacle is the Front Range of the Rocky Mountains, seen through clouds at the bottom of the picture.
Click on image for full size
Courtesy of UCAR Digital Image Library
Lenticular clouds form on the downwind side of air flowing over a large mountain or mountain range. Unlike most clouds that move across the sky, lenticular clouds stay in one place as air appears to blow through them. What is really happening is that the cloud forms on the side closest to the mountains where air is uplifting over the top of the mountain. Then the cloud moves with the wind and evaporates on the downwind side, so it appears stationary even though air is moving through the cloud.
As this photo on this page shows, lenticular clouds are lens-shaped and resemble flying saucers.
Shop Windows to the Universe Science Store!
The Fall 2009 issue of The Earth Scientist
, which includes articles on student research into building design for earthquakes and a classroom lab on the composition of the Earth’s ancient atmosphere, is available in our online store
You might also be interested in:
Wind is moving air. Warm air rises, and cool air comes in to take its place. This movement creates different pressures in the atmosphere which creates the winds around the globe. Since the Earth spins,...more
One process which transfers water from the ground back to the atmosphere is evaporation. Evaporation is when water passes from a liquid phase to a gas phase. Rates of evaporation of water depend on factors...more
Altocumulus clouds (weather symbol - Ac), are made primarily of liquid water and have a thickness of 1 km. They are part of the Middle Cloud group (2000-7000m up). They are grayish-white with one part...more
Altostratus clouds (weather symbol - As) consist of water and some ice crystals. They belong to the Middle Cloud group (2000-7000m up). An altostratus cloud usually covers the whole sky and has a gray...more
Cirrocumulus clouds (weather symbol - Cc) are composed primarily of ice crystals and belong to the High Cloud group (5000-13000m). They are small rounded puffs that usually appear in long rows. Cirrocumulus...more
Cirrostratus (weather symbol - Cs) clouds consist almost entirely of ice crystals and belong to the High Cloud (5000-13000m) group. They are sheetlike thin clouds that usually cover the entire sky. The...more
Cirrus (weather symbol - Ci) clouds are the most common of the High Cloud (5000-13000m) group. They are composed entirely of ice and consist of long, thin, wispy streamers. They are commonly known as...more