TAFs can be more accurate than numerical weather forecasts, since they take into account local, small-scale, geographic effects.
[3] TAFs are issued at least four times a day, every six hours, for major civil airfields: 0000, 0600, 1200 and 1800 UTC,[4] and generally apply to a 24- or 30-hour period, and an area within approximately five statute miles (8.0 km) (or 5 nautical miles (9.3 km) in Canada) from the center of an airport runway complex.
In the United Kingdom, TAFs for military airfields use colour states as one of the change criteria.
If information sources, such as surface observations, are missing, unreliable, or not complete, forecasters will append AMD NOT SKED to the end of a TAF.
The United States Air Force employs active duty enlisted personnel as TAF writers.