FAA Ground School Practice Test

What is used to mark the crests of standing mountain waves?

1. Thin cirrus clouds

2. Dense cumulus clouds

3. Standing lenticular clouds

4. Stratus clouds

The correct answer is: Standing lenticular clouds

Standing lenticular clouds are formed when moist air flows over mountain ranges and creates a wave pattern on the leeward side. These clouds can appear as distinct, lens-shaped formations and are associated with the crests of standing mountain waves. As air rises and cools, condensation occurs, leading to the formation of these clouds at the wave crests. Thin cirrus clouds typically indicate high-altitude moisture but do not specifically relate to mountain wave activity. Dense cumulus clouds suggest significant vertical development, often associated with instability, rather than the stable conditions present in standing mountain waves. Stratus clouds are uniform and layer-like, typically forming in stable air conditions, and do not indicate the turbulence or wave pattern associated with standing lenticular clouds. Understanding the characteristics of these cloud types helps in recognizing weather patterns and air disturbances influenced by the terrain, which is crucial for flight safety and planning.