When you see a cloud with a dark, flat base and a top that spreads out like a blacksmith’s anvil, you’re looking at a cumulonimbus. This is a classic sign that a thunderstorm is forming, and ...

When the anvil of a cumulonimbus cloud starts to spread out, that’s when mammatus clouds can form. As these clouds spread out, they allow warm air to move upwards into the bottom of the cloud.

A thunderstorm with an anvil cloud near Brampton, Ontario, in June 2023. (Photo courtesy of Jarrett T.) MUST SEE: Super-cold thunderstorm sets record with -111°C cloud temperature.

Now there can be variations of the anvil cloud., Just like cumulus clouds, some can make rain. Some don’t. Some can be darker and produce thunderstorms, but they don’t have to.

Flying high over the ground in a plane, a thunderstorm's anvil cloud might be the last thing you want to see, but it's exactly what a group of scientists conducting an airborne mission were ...

After severe storms swept through the Houston metro area on Tuesday, an eye-catching display of mammatus clouds — a rare and distinctive pouch-like cloud formation — filled the skies over ...

Cumuliform Anvil: A thunderstorm anvil with visual characteristics resembling cumulus-type clouds. ... (usually a thunderstorm). Rising cloud motion often can be seen in the leading (outer) ...

Anvil cloud: At the highest level of a mature thunderstorm, an anvil cloud will form.It is a flat, white cloud that spreads horizontally once it reaches the stratosphere and can no longer grow ...

Towering, dense clouds with a flat, anvil-shaped top. Develops from cumulus clouds and can reach great heights, often associated with thunderstorms. Indicates severe weather, such as thunderstorms ...

The combination of an overshooting top and anvil cloud creates the ‘classic’ view of a thunderstorm that’s in just about every textbook and stock image. Powerful updrafts can support powerful hazards.