photo #5169568

On the drive to work in Longmont, Colorado, J. Bragstad (Cloud Appreciation Society Member 52,430) watched as these clouds developed over the mountains. At the traffic lights, she finally had a chance to take a photo. These are Altocumulus lenticularis clouds, formed as a moist airstream flows up and over raised ground, developing a wavelike path in the stable air beyond the terrain, with the disc- and lozenge-shaped clouds forming at the wave peaks. When layers of moist air intercut with layers of drier air, you may also get stacks of lenticularis clouds. These are known as lenticularis duplicatus, or pile d’assiettes, French for ‘stack of plates’. Left out in the Colorado Sun, these plates should dry in no time.