Altocumulus lenticularis (d-050215-012)
In gallery: Photos of the month (2005)
Related photos: Clouds
Various cloud forms
The lens-shaped clouds in this photo are called lenticularis, and are at middle-high altitude. Lenticularis clouds are likely in mountainous regions, such as these over New Mexico, when upper-level winds are very strong. Mountains create disturbances (waves) in the airflow that propagate to high altitudes, forming stationary lenticularis clouds on the wave crests.
Photographed in New Mexico (USA) on February 15 using a Nikon D100 digital camera. These clouds are sometimes seen in this region prior to an approaching low-pressure system.