Pilot Report

A Pilot Report (PIREP) is a weather observation made by a pilot during flight and relayed to ATC or flight service, providing real-time information about conditions at altitude that ground-based observations cannot detect.

PIREPs are coded as UA (routine) or UUA (urgent) and typically include:

Location: Relative to a navaid or fix
Time: UTC of observation
Altitude/Flight Level
Aircraft type
Sky conditions: Cloud bases and tops
Turbulence: Intensity (light, moderate, severe, extreme) and type
Icing: Type (rime, clear, mixed) and intensity
Visibility and weather

PIREPs are invaluable for other pilots and forecasters. Pilots are encouraged to submit PIREPs, especially regarding turbulence and icing.