Meteorology: Understanding the Atmosphere            Ackerman and Knox



Mountain-generated gravity waves are visible, even by satellite, many times each year over the central Appalachian Mountains when near-surface winds blow perpendicular to the mountain ridges. The mountainous regions west of Washington, DC, often produce these waves, which are called “lee waves” because they are downwind of the mountains. The animation below shows a classic example of the clouds produced by these waves; the wind in the figure is blowing toward the southeast. Notice how the lee wave mountains appear to remain in place.