Wave and Orographic Clouds

6. Looking upwind at a lee-wave cloud (foreground), Boulder, Colorado.
Stacks of lenticular clouds give the band a bumpy appearance.
In the distance is a wave cloud band capping the Continental Divide,
which is the main orographic barrier. The mountains in the foreground,
which appear larger in the photo, are actually smaller foothills.
(Photo courtesy of Dale R. Durran.)