In order to plan ahead at your facility, you must know what the current and predicted
weather conditions will be. Forecasting is an extremely important tool. In order to plan
effectively, you must know what forecasts are available, how to use them, and how the
forecasted weather will impact your facility.
Forecasts come in several forms. Table1-23 lists forecasts to help you understand the
different types of forecasts that are available.
Terminal aerodrome forecast issued by the NWS for specific locations
(terminal) four times a day. A TAF is valid for 24 hours. Each TAF
replaces the previous TAF and is amended as needed.
Area forecast issued by the NWS that covers an entire region, such as
the Mid-Atlantic states. Describes anticipated cloud, weather, and icing
conditions. FAs are issued four times a day and are valid for a period of
24 hours. FAs start with a synopsis that describes the movements of
significant fronts, pressure systems, and circulation patterns.
Winds and temperature aloft forecast issued by the NWS twice a day.
FDs assist pilots in determining estimated times of arrival and fuel
consumption. FDs can also give pilots an idea of where their aircraft may
encounter icing conditions.
Table 1-23 -- Types of forecasts
Change groups indicate a change in any or all TAF elements from the predominant
condition. Each change group indicates the time during which the changes are forecast
to occur. The TAF uses four change groups as listed in Table 1-24.