The date and time format for Terminal Aerodrome Forecasts (TAFs) has changed. As of 00 UTC on November 5th, the duration of TAFs issued for 32 major airports throughout the United States increased from 24 hours to 30 hours to support long-haul flight operations. To accomodate this extended TAF duration, the date/time format for ALL TAFs has changed, even for those airports that maintained a 24-hour TAF duration. Specifically, the format change involves identifying the date associated with each time group. As illustrated in the examples below, the previous TAF format is modified by adding the appropriate date before the forecast hour.
New TAF Format
The new TAF format includes a date with every time group.
This TAF in the previous format:
The format change only affects the date/time groups in the TAFs. There is no change in format to any of the weather elements. As shown above, the valid time of a TAF changes from the present ddhhhh to ddhh/ddhh. For TEMPO and PROB groups, hhhh changes to ddhh/ddhh. FM groups change from hhmm to ddhhmm. (dd is the date of the month; hh is the hour; mm represents minutes)
The TAF for the Central Nebraska Regional Airport (KGRI) in Grand Island remains 24 hours in duration, but has changed to the new date/time format.
Additional information and examples of the TAF format change can be found at the following links: