Cumulonimbus Mammatus

Above: Cumulonimbus Mammatus

Cumulonimbus Mammatus

When a pilot sees a cumulonimbus mammatus cloud, they land immediately because this is probably one of the scariest clouds that a person can encounter. This is not just your average storm cloud – it is a tornado cloud. This cloud signifies a very bad storm is coming on.

What are cumulonimbus mammatus clouds?

Generally speaking, a mammatus cloud, commonly referred to as a breast cloud or mammary cloud is a small could that hangs in clusters from the bottom of another cloud. When it is attached to the bottom of a cumulonimbus cloud, it is an amplifier of what the cloud itself signifies. It is most commonly associated with the anvil clouds, which are particularly strong and significant of mature storms.

What height are cumulonimbus mammatus clouds found?

These clouds are usually found at the bottom of cumulonimbus clouds of many types, which start at about 500 to 10,000 feet in the air. They live only at these usually fairly low altitudes. You won’t find one anywhere else.

Classification of cumulonimbus mammatus clouds

A mammatus cloud is a general type on its own and takes on the name of the particular cloud to which it attaches itself. The name is attached in the same manner – right at the end. In this case, the cumulonimbus mammatus is considered a specific type of a cumulonimbus cloud.

How are cumulonimbus mammatus clouds formed?

When a storm matures, it obviously gets more dangerous. Significant updrafts and downdrafts can create the right environment for a supercell storm cloud. When this happens, a tornado can actually arise. This is when the storm cloud itself gets these udder-like additions on the very bottom.

What do cumulonimbus mammatus clouds look like?

Cumulonimbus mammatus clouds are given the nickname mammary clouds for a reason. They look very much like udders on the bottom of a cow. These round bumps line the bottom of a cloud. Other characteristics of these clouds are:

  • They are usually very small and dark, and can look a little threatening, but still interesting to see for many people.


  • They always have a very significant look when they form on the bottom of a very large cloud such as the cumulonimbus.

How common are cumulonimbus mammatus clouds?

These clouds, thankfully, are not that common at all. Although mammatus clouds in general are pretty common, cumulonimbus mammatus clouds are not as common as a specific type. They can only be seen in a very mature and possibly dangerous storm. This may be a cloud that we don’t want to see very much of anyway because of what it signifies.

Where can I see cumulonimbus mammatus clouds?

If you are looking for a cumulonimbus mammatus cloud, you are outside in a particular time that you probably shouldn’t be. These clouds are only present in very mature storms that signify tornadoes in the future. You can look at the very bottom of the super large storm cloud to see these, but do so briefly and take cover after you spot one and take your picture.

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