Among all cloud types, cumulonimbus stands out for its size and power. These clouds grow vertically into towering structures that can reach the tropopause. Their tops often spread into anvil shapes when they hit the stable layer above.

Strong updrafts feed the cloud with moisture, while downdrafts carry rain, hail, or even tornadoes toward the surface. Lightning is common because charge separation occurs readily inside the turbulent interior. A single cell may last less than an hour, yet organized systems can persist much longer.

Pilots avoid flying through cumulonimbus because of extreme turbulence, icing, and hail. On the ground the storms produce heavy rain, strong winds, and sometimes flash flooding. Satellite and radar imagery make these clouds easy to identify by their height and intensity.

• Towering thunderstorm cloud
• Produces heavy rain, hail, lightning
• Can reach tropopause with anvil top
• Associated with severe weather