Definition
A Terminal Aerodrome Forecast (TAF) is a concise weather forecast issued for the airspace within a five statute mile radius of an airport, typically valid for 24 or 30 hours and updated four times per day. It describes expected surface wind, visibility, weather phenomena, and cloud conditions, including any forecast changes during the valid period.
Plain English
A short weather forecast for the area right around an airport, telling pilots what to expect at that airport over roughly the next day.
Context Anchor
Pilots use TAFs during preflight weather planning, especially when deciding whether the departure airport, destination, or alternate airport is suitable for the planned flight.
Derivation
Terminal refers to the airport (the terminal point of a flight). Aerodrome is the older international word for airport, still used in ICAO documents. Forecast comes from Old English meaning 'to plan beforehand.' Together: a planned-ahead weather picture for the airport area.
Why Pilots Care
TAFs let pilots determine whether current or forecast weather meets landing minimums and whether an alternate airport will be required.
Intuition Check
A TAF is not a current weather report. It is a forecast of what the airport weather is expected to do during a future period.
Example Sentence 1
The TAF for the destination showed visibility dropping to one mile in fog around the planned arrival time, so the pilot filed an alternate.
Example Sentence 2
The updated TAF showed a temporary drop in ceiling that required the pilot to add an alternate airport to the flight plan.