Downdrafts Associated with Terrain/Cloud

Downdrafts are some of the main causes of in-flight turbulence for aircraft, and are one of the reasons why aircraft try to avoid geographic regions or bad weather. Extreme cases, known as mountain waves, cold fronts, downbursts and microburst are responsible for many aircraft crashes.

Geographic regions create downdrafts from mountain waves, cold fronts, katabatic wind and lee side turbulence from wind passing over mountain ranges (mechanical turbulence).