Definition
Columns or currents of air moving downward relative to the ground. In aviation weather, downdrafts are areas where air is descending, often associated with thunderstorms, mountain lee sides, or rapidly cooling air, and they can push an aircraft toward the ground faster than it would normally descend.
Plain English
Air that is moving downward. When an aircraft flies through it, the air is sinking, which tends to take the aircraft down with it.
Context Anchor
Pilots consider downdrafts when evaluating weather, terrain, and other environmental conditions before and during a flight.
Derivation
From 'down' (toward the ground) and 'draft' (a current or flow of air, from Old English 'dragan' meaning to draw or pull). A downdraft is literally air being drawn downward.
Why Pilots Care
Can produce abrupt altitude loss, especially hazardous near terrain or during low-altitude operations.
Grounding Statement
Imagine flying along level and steady, then suddenly the aircraft sinks even though you haven't changed anything -- the air itself is moving down, and you're going with it.
Intuition Check
Do not think of downdrafts as ordinary wind blowing across the ground. In aviation, downdrafts are air moving downward, which can make the aircraft sink.
Example Sentence 1
On the lee side of the ridge, the pilot encountered a strong downdraft and had to turn away from the terrain to recover altitude.
Example Sentence 2
Mountain downdrafts on the lee side forced the aircraft to climb higher before crossing the ridge.