A Terminal Aerodrome Forecast, or TAF, is a concise report of the expected weather conditions at an airport. Think of it as a weather story, told in a special code. This code is standardized across the globe, allowing any pilot, anywhere, to understand the forecast for their destination.

Every TAF follows a consistent structure. It starts with the airport identifier, followed by the date and time the forecast was issued, and the period it's valid for. The main body of the report then details the key weather elements: wind, visibility, significant weather, and sky conditions.

Let's break down that example. KLAX is the airport (Los Angeles International). 151720Z means it was issued on the 15th of the month at 17:20 Zulu time (Coordinated Universal Time). The forecast is valid from the 15th at 18:00Z until the 16th at 24:00Z. The rest describes the weather itself.

Wind is one of the most critical factors in aviation. In a TAF, it's reported with direction and speed.

• Direction: A three-digit number shows the direction the wind is coming from, in degrees relative to true north. A wind from the west would be 270.
• Speed: Following the direction, a two or three-digit number indicates the wind speed in knots (KT). Gusts are noted with a 'G' and the peak gust speed, like 27015G25KT.

In our example, 27010KT means the wind is forecast to be from 270 degrees (west) at 10 knots.

Visibility tells a pilot how far they can see. It's reported in statute miles (SM). P6SM means visibility is expected to be "plus 6 statute miles," or excellent. If visibility were lower, it might read 3SM (3 statute miles) or 1/2SM (half a statute mile).

Any significant weather phenomena are included using a set of standardized codes. These codes describe precipitation, obstructions to visibility, and other events. They can be combined to indicate intensity or type. For example, -RA means light rain, while +TSRA means a thunderstorm with heavy rain.

Sky condition describes cloud cover. The report specifies the amount of sky covered by clouds and the height of the cloud base in hundreds of feet above ground level (AGL). For example, BKN030 means a "broken" cloud layer at 3,000 feet AGL. If no significant clouds are expected, the report will use SKC (Sky Clear) or CLR (Clear, below 12,000 feet).

Each of these elements combines to paint a detailed picture of the expected conditions, allowing flight crews to make critical decisions about timing, fuel, and alternate routes.

Ready to test your knowledge?

Understanding the structure is the first step to becoming proficient at reading these vital aviation forecasts.