Definition
In a PIREP (Pilot Report), /TB is the field identifier introducing turbulence information reported by the pilot. The letters following /TB describe the intensity and type of turbulence encountered (for example, /TB LGT, /TB MOD-SEV CHOP).
Plain English
It is the label inside a pilot weather report that says: 'Here comes the turbulence information.' Whatever follows tells you how rough the air was.
Context Anchor
Seen when reading or decoding pilot weather reports, especially when checking ride conditions along a route or at a planned altitude.
Derivation
The slash separates fields in a PIREP. 'TB' is shorthand for Turbulence. PIREPs use a fixed sequence of slash-coded fields so any reader can scan straight to the part they need.
Why Pilots Care
Turbulence affects passenger comfort, aircraft control, and structural loads, so reported locations help pilots choose safer altitudes or routes.
Intuition Check
/TB is not a command and not a forecast by itself. It is the turbulence section of a report from a pilot who encountered those conditions.
Example Sentence 1
The PIREP read /TB MOD 080, meaning the pilot reported moderate turbulence at 8,000 feet.
Example Sentence 2
Checking the latest reports, the pilot noted /TB MOD near the pass and climbed to avoid it.