Which document provides information about winds aloft for a specified flight?

The correct response is the Winds Aloft Forecast (FD) because this document specifically provides detailed information about wind speeds and directions at various altitudes above the surface. This information is crucial for pilots as it helps them understand the expected winds during their flight, enabling them to plan their route more efficiently and adjust their fuel calculations and handling of the aircraft accordingly.

In contrast, the Terminal Aerodrome Forecast (TAF) primarily focuses on weather conditions in the vicinity of an airport, such as visibility and cloud cover, but does not include details about winds aloft. The Aerodrome Report (METAR) is a routine weather report providing surface weather observations, which also do not offer information about higher altitudes. The Flight Service Station (FSS) is a resource for pilots to obtain various types of flight information, but it does not specifically generate winds aloft data; rather, it disseminates data from sources like the Winds Aloft Forecast.