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downdraft
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Diagram of a thunderstorm showing a towering cumulonimbus cloud with labeled features including warm updrafts rising, cool downdrafts falling, precipitation at the base, and an anvil-shaped top spreading near the tropopause. Colored arrows indicate the movement of warm and cool air within the storm. A faint scale on the right marks cloud height in kilometers.
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downdraft

meteorology
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Diagram of a thunderstorm showing a towering cumulonimbus cloud with labeled features including warm updrafts rising, cool downdrafts falling, precipitation at the base, and an anvil-shaped top spreading near the tropopause. Colored arrows indicate the movement of warm and cool air within the storm. A faint scale on the right marks cloud height in kilometers.
thunderstorm: structure When the atmosphere becomes unstable enough to form large powerful updrafts and downdrafts (as indicated by the red and blue arrows), a towering thundercloud is built up. At times the updrafts are strong enough to extend the top of the cloud into the tropopause, the boundary between the troposphere (or lowest layer of the atmosphere) and the stratosphere. Click on the icons along the left-hand side of the figure to view illustrations of other phenomena associated with thunderstorms.

In meteorology, downdrafts are downward-moving air currents. They can be caused by several factors, including the daytime heating of the ground, which makes surface air warmer and less dense, causing it to rise and be replaced by cooler, descending air. Downdrafts also occur as part of the turbulence created when air flows over mountains.1

Strong downdrafts are a significant feature of thunderstorms. In a mature storm, they are present alongside updrafts and are caused by cooling and falling precipitation. These downdrafts carry cold, dense air that spreads out at the ground, creating a cold air wedge. The sudden changes in wind direction associated with downdrafts near the ground pose a risk to aircraft during landing and takeoff. Intense downdrafts are known as downbursts or microbursts.1

When air sinks in a thunderstorm, it remains cool due to the evaporation of water and melting ice. This sinking air is denser than its surroundings and can reach the ground with a horizontal velocity much higher than the surface wind. This results in a gust front, characterized by a sudden drop in air temperature and an increase in wind speed as the cool air spreads out ahead of the storm.2

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2 Britannica Sources
  1. updraft and downdraft
  2. thunderstorm - Downdrafts and gust fronts

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