[Ref Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 12-16]

What’s “Towering Cumulus (TCU)”?

Towering Cumulus (TCU) is a type of cloud with extensive vertical development.

TCU indicate areas of instability in the atmosphere, and the air around and inside them is turbulent. TCU is potential to develop into cumulonimbus (CB) or thunderstorms.