Lesson 5 Review
TAFs may be issued at non-standard times to update a forecast, correct a forecast or to issue a delayed forecast due to a break in airport observations. They are issued on an as needed basis.
The three (3) types of unscheduled terminal forecasts issued are:
- Amended – used to amend (update) a TAF in between scheduled TAF issuances.
- Corrected – used to send out a correction to a previously issued TAF.
- Delayed – used when the scheduled TAF was delayed for some reason.
Unscheduled TAFs follow the same format and contain the same forecast elements as scheduled issuances. The primary difference is unscheduled TAFs contain additional syntax (AAA, CCA, RRA) in the WMO Header area to identify the message issuance type.
TAF locations that receive limited observations need to include the remark "AMD NOT SKED" along with the time of the last observation or when observations are to resume after the last forecast group.
Congratulations. You have reached the end of Lesson 5.