Cauda clouds are a distinctive feature associated with severe thunderstorms, particularly supercells.
These low-level, horizontal, tail-shaped clouds extend from the main precipitation region of a supercell cumulonimbus cloud to the murus (wall cloud).
Their presence indicates strong convective activity and potential severe weather conditions.

Characteristics of Cauda Clouds
- Base Altitude: Typically forms at low levels, extending horizontally from the main precipitation region of a supercell cumulonimbus cloud.
- Top Altitude: The top of the cauda cloud is generally at the same height as the base of the murus (wall cloud), indicating a horizontal extension rather than vertical development.
- Shape: Cauda clouds are horizontal, tail-shaped clouds that extend from the main precipitation region of a supercell cumulonimbus cloud to the murus (wall cloud).
- Texture: The cloud may appear as a defined horizontal cloud band or as horizontally aligned cloud tags attached to the cumulonimbus murus cloud type.
- Color: Typically appears darker due to the dense concentration of water droplets, but color can vary depending on lighting and atmospheric conditions.
- Etymology: The term “cauda” is derived from the Latin word for “tail,” reflecting the cloud’s characteristic tail-like appearance extending from the wall cloud.
- Precipitation: Cauda clouds themselves are not significant producers of precipitation. However, they are associated with the main precipitation region of a supercell cumulonimbus cloud, which can produce heavy rainfall and severe weather conditions.
Formation and Dynamics
Cauda clouds form in association with supercell thunderstorms, which are characterized by their rotating updrafts and well-defined structures.
The cauda cloud extends horizontally from the main precipitation region to the murus (wall cloud), indicating strong inflow of warm, moist air and significant convective activity.
The presence of a cauda cloud suggests that the storm is well-organized and has the potential to produce severe weather, including tornadoes.
Historical Context
The cauda cloud was officially recognized as a distinct cloud feature by the World Meteorological Organization (WMO) in the 2017 edition of the International Cloud Atlas. This addition highlighted the importance of recognizing and categorizing various cloud features associated with severe weather phenomena.

Observations and Phenomena
- Severe Weather Indicator: The presence of a cauda cloud is a strong indicator of severe weather conditions, including the potential for tornadoes. Meteorologists closely monitor the development of cauda clouds to assess the severity of thunderstorms.
- Visual Characteristics: Cauda clouds are often observed as horizontal, tail-shaped clouds extending from the main precipitation region of a supercell cumulonimbus cloud to the murus (wall cloud).
Distinguishing Cauda Clouds from Similar Cloud Forms
While cauda clouds share similarities with other cloud formations, they can be distinguished by their unique characteristics:
- Flumen (Beaver’s Tail): Flumen clouds are larger inflow bands feeding into the updraft base of a storm and are typically higher in altitude compared to cauda clouds.
- Wall Cloud (Murus): The murus (wall cloud) is a well-defined, vertically oriented cloud feature associated with severe thunderstorms. The cauda cloud extends horizontally from the murus, indicating a different orientation and structure.
Further Information
- Geographic Distribution: Cauda clouds are observed in regions prone to supercell thunderstorms, including parts of the United States, Australia, and other areas with similar climatic conditions.
- Scientific Research: Ongoing research aims to better understand the formation mechanisms and dynamics of cauda clouds, enhancing forecasting capabilities for severe weather events.


