When wind flows over a mountain, what happens to the air on the leeward (downwind) side?

Why: The Remote Pilot Study Guide explains that while wind flows smoothly up the windward side of a mountain, "the wind on the leeward side does not act in a similar manner. As the air flows down the leeward side of the mountain, the air follows the contour of the terrain and is increasingly turbulent. This tends to push an aircraft into the side of a mountain." The stronger the wind, the greater the downward pressure and turbulence become.

• Assumes leeward airflow mirrors the smooth windward updrafts, when the study guide specifically contrasts the two as behaving differently.
• Invents a calm pocket of air that the source material does not describe; leeward mountain flow is characterized by turbulence, not stillness.