What type of cloud is identified by the abbreviation CB in a METAR report?

The abbreviation CB in a METAR report stands for Cumulonimbus clouds. These are towering clouds often associated with thunderstorms and severe weather. Cumulonimbus clouds can extend high into the atmosphere, reaching the stratosphere, and are characterized by their anvil-shaped tops. They typically bring heavy rainfall, lightning, and sometimes severe weather phenomena like hail or tornadoes. Recognizing this abbreviation is essential for understanding potential weather conditions, especially when assessing flight safety or predicting rapid weather changes. This distinguishes Cumulonimbus from other cloud types, such as Cirrus, Cumulus, and Stratus, which have their own unique characteristics and weather implications.