METAR weather code reference for FC (Funnel Cloud / Tornado / Waterspout)
A rotating column of air. When reported as FC it indicates a funnel cloud (not touching the ground) or waterspout. When reported as +FC, it indicates a tornado or waterspout. This is one of the most urgent weather reports in aviation, demanding immediate avoidance.
Here are common ways FC appears in real METAR observations:
FC+FCFC TSThese METAR codes are commonly seen alongside FC or describe related weather phenomena:
A convective storm producing lightning and thunder. In METAR reports, TS indicates that thunder has been heard at the station within the observation period. Thunderstorms are among the most dangerous weather phenomena for aviation, bringing turbulence, wind shear, hail, heavy rain, and microbursts.
A sudden increase in wind speed of at least 16 knots, the speed rising to 22 knots or more and lasting for at least one minute. Squalls are associated with thunderstorms and frontal passages. They can cause rapid changes in wind direction and speed, creating hazardous crosswind conditions for landing and takeoff.