The Aviation Forecast Discussion is a text interruption from a meteorologist of the local weather conditions.
Aviation Forecast Discussions (AFD) are issued by each weather service forecast office (WFO) to describe the weather conditions within their region as it relates to the creation of the TAF. These are useful for additional aviation related issues that cannot be encoded into the TAF. The discussion also gives some reasoning behind the forecast. These are generated roughly every 6 hours and corresponds to the release of the latest TAFs for that office. The aviation forecast discussion explains the aviation forecast in greater detail than a traditional TAF. It highlights possible hazards in the forecast that may not be specifically mentioned in the TAF, possibly due to a low level of confidence that the event will occur. The frequency of aviation discussion issuances varies between WFOs.